.. _sec:settings: Changing plot settings ====================== .. _sec:menu: Menus ----- The plot settings may be changed in a series of submenus: .. image:: figs/menu.png :width: 50.0% Options can be saved using the (s)ave option from the menu: .. image:: figs/menu.png :width: 50.0% .. _sec:menu-s: (s)aving your settings ---------------------- .. image:: figs/menu-s.png :width: 50.0% - Pressing ``s`` saves current options to ``splash.defaults``. - Delete ``splash.defaults`` to revert all settings - Pressing ``S`` saves both ``splash.defaults`` and ``splash.limits`` (and any other files). - Typing ``sa`` or ``Sa`` gives a “save-as” option, changing the prefix of saved files - read defaults files saved with a different prefix using the ``-p`` option Example: :: Please enter your selection now (y axis or option):SA enter prefix for filenames: (default="blah"): default options saved to file blah.defaults saving plot limits to file blah.limits saving units to blah.units Read this back using: :: splash -p blah Files saved by splash can also be edited manually. For example, ``splash.limits`` is a simple two-column ascii file containing minimum and maximum plot limits for each column. To reset the plot limits simply delete the ``splash.limits`` file. .. _sec:multiplot: set (m)ultiplot --------------- .. image:: figs/menu-m.png :width: 50.0% .. _sec:multiplotsetup: Plotting more than one column from the same file on the same page (multiplot) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Press ’m’ (:ref:`sec:multiplot`) from the main menu to set up a multiplot. Once you have gone through the options to set up a multiplot, to actually plot what you have set simply type the number of the column corresponding to “multiplot” at the :math:`y-`\ axis prompt. .. important:: A “multiplot” - multiple columns plotted from the same file - is different to plotting “multiple plots per page” - divide the plotting page up into panels. The number of panels across and down on a page can be changed (see :ref:`sec:nacrossndown`) irrespective of whether or not you are also plotting multiple columns from the same file. Plotting each particle type in a different panel (multiplot) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ To make a plot using different particle types in each panel (e.g. gas density in one panel, dust or dark matter density in another), use ’m’ :ref:`sec:multiplot` from the main menu. If multiple types are present in the data read, the option appears to specify the particular types you want to use for each plot. For example, after pressing ‘m’ at the main menu we eventually arrive at the question: :: use all active particle types? (default=yes): n Answering ``no`` brings up a possible list of types: :: 1: use gas particles 2: use ghost particles 3: use sink particles 4: use star particles 5: use unknown/dead particles Enter type or list of types to use ([1:5], default=1): 1,3 Thus entering e.g. ``1,3`` specifies that only gas and sink particles should be used for this plot. .. important:: This is more specific than simply turning particle types on and off for *all* plots, which can be achieved via the ``turn on/off particles by type`` option in the :ref:`sec:menu-o` (see :ref:`sec:plotparticlesbytype`). .. _sec:menu-d: (d)ata options -------------- .. image:: figs/menu-d.png :width: 50.0% The following can all be achieved from the d)ata options menu: Re-reading the initial data / changing the dump file ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Just exit splash and restart with the new dump file name on the command line (remember to save by pressing ’S’ from the main menu before exiting to save both the current settings and the plot limits – then you can continue plotting with the current settings using a new dump file). If you have placed more than one file on the command line, then pressing space in :ref:`sec:interactive` will read (and plot) the next file (press ’h’ in :ref:`sec:interactive` for a full list of commands - you can move forwards and backwards using arbitrary jumps). For non-interactive devices or where :ref:`sec:interactive` is turned off dump files are cycled through automatically, plotting the same plot for each file/timestep. .. _sec:subsetofsteps: Using only a subset of data files / plotting every :math:`n-`\ th dump file ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ To plot a subset of the data files in \*any\* order, see :ref:`sec:selectedstepsonly`. Of course, another way to achieve the same thing is to explicitly order the files on the command line. A method I often use is to write all filenames to a file, e.g. :: > ls DUMP* > splash.filenames then edit the file to list only the files I want to use, then invoke splash with no files on the command line: :: > splash which will use the list of files specified in the ``splash.filenames`` file. .. _sec:buffering: Plotting more than one file without re-reading the data from disk ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For small data sets (or a small number of dump files) it is often useful to read all of the data into memory so that you can move rapidly forwards and backwards between dumps (e.g. in :ref:`sec:interactive`, or where both dumps are plotted on the same page) without unnecessary re-reading of data from disk. This is achieved with the command line flag:: splash --buffer file_0* (provided you have the memory of course!!). Non-buffered data means that only one file at a time is read. .. _sec:calc: Calculating additional quantities not dumped ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Turn ``calculate extra quantities`` on in the :ref:`sec:menu-d`. New columns of data can be created as completely arbitrary functions of the data read from the SPH particles. Option ``d1`` in the data menu leads, for a typical data read, to a prompt similar to the following: :: Specify a function to calculate from the data Valid variables are the column labels, 't', 'gamma', 'x0', 'y0' and 'z0' (origin setting) Spaces, escape sequences (\d) and units labels are removed from variable names Note that previously calculated quantities can be used in subsequent calculations Examples based on current data: r = sqrt((x-x0)**2 + (y-y0)**2 + (z-z0)**2) pressure = (gamma-1)*density*u |v| = sqrt(vx**2 + vy**2 + vz**2) Enter function string to calculate (blank for none) (default=""): Thus, one can for example calculate the pressure from the density and thermal energy according by copying the second example given. .. hint:: Function calculation is completely general and can use any of the columns read from the file, the time for each step (‘``t``’), the adiabatic index :math:`\gamma` (‘``gamma``’) and the current origin setting (``x0``, ``y0`` and ``z0``). Previously calculated quantities can also be used - e.g. in the above example we could further compute, say, an entropy variable using ``s=pressure/density^gamma`` after the pressure has been specified. The resultant quantities appear in the main splash menu as standard columns just as if they had been read from the original data file. The origin for the calculation of radius can be changed via the ``rotation on/off/settings`` option in the :ref:`sec:menu-x`. If particle tracking limits are set (see :ref:`sec:track`) the radius is calculated relative to the particle being tracked. If you simply want to multiply a column by a fixed number (e.g. say you have sound speed squared and you want to plot temperature) - this can also be achieved by defining a unit for the column (i.e., a factor by which to multiply the column by) – see :ref:`sec:physicalunits` for details. The corresponding label can be changed by creating a ``splash.columns`` file (or for the ascii read just a file called ‘columns’) containing labels which are used to override the default ones from the data read (one per line) – see :ref:`sec:columnsfile` for more details. See also :ref:`sec:geom` for how to transform vectors (and positions) into different coordinate systems. .. _sec:physicalunits: Plotting data in physical units ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Data can be plotted in physical units by turning on the ``use physical units`` option in the :ref:`sec:menu-d`. The settings for transforming the data into physical units may be changed via the ``change physical unit settings`` option in the :ref:`sec:menu-d`. (see :ref:`sec:changingunits`) For some data reads (phantom, sphNG, magma) the scalings required to transform the data into physical units are read from the dump file. These are used as the default values but are overridden as soon as changes are made by the user (that is, by the presence of a ‘splash.units’ file) (see :ref:`sec:changingunits`). .. important:: Physical units are now ON by default in v3.x of SPLASH if they are set by the data read. You can use this option to revert to code units Rescaling data columns ~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:physicalunits`. .. _sec:columnsfile: Changing the default column labels ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The labelling of columns is usually automatic in the data format read (for ascii files labels will be read from the file header). Aside from changing the labels in the ``read_data`` file specific to the format you are reading, it is also possible to override the labelling of columns at runtime by creating a file called ``splash.columns`` (or with a different prefix if the ``-p`` command line option is used), with one label per line corresponding to each column read from the dump file, e.g. :: column 1 column 2 column 3 my quantity another quantity .. warning:: Labels in the ``splash.columns`` file *will not* override the labels of coordinate axes or labels for vector quantities (as these require the ability to be changed by plotting in different coordinate systems – see :ref:`sec:geom`). Plotting column density in g/cm\ :math:`^{2}` without having x,y,z in cm ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:changingunits`. In addition to units for each column (and a unit for time – see :ref:`sec:timeunits`) a unit can be set for the length scale added in 3D column integrated plots. The prompt for this appears after the units of either :math:`x`, :math:`y`, :math:`z` or :math:`h` has been changed via the ``change physical unit settings`` option in the :ref:`sec:menu-d`. The length unit for integration is saved in the first row of the splash.units file, after the units for time. See :ref:`sec:setprojlabel` for details on changing the default labelling scheme for 3D column integrated (projection) plots. .. _sec:changingunits: Changing physical unit settings ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The settings for transforming the data into physical units may be changed via the ``change physical unit settings`` option in the :ref:`sec:menu-d`. To apply the physical units to the data select the ``use physical units`` option in the :ref:`sec:menu-d`. The transformation used is :math:`new= old*units` where ``old`` is the data as read from the dump file and ``new`` is the value actually plotted. The data menu option also prompts for a units label which is appended to the usual label. Brackets and spaces should be explicitly included in the label as required. Once units have been changed, the user is prompted to save the unit settings to a file called ``splash.units``. Another way of changing units is simply to edit this file yourself in any text editor (the format is fairly self-explanatory). To revert to the default unit settings simply delete this file. To revert to code units turn ``use physical units`` off in the :ref:`sec:menu-d`. .. hint:: A further example of where this option can be useful is where the :math:`y-`\ axis looks crowded because the numeric axis labels read something like :math:`1\times 10^{-4}`. The units option can be used to rescale the data so that the numeric label reads :math:`1` (by setting :math:`units=10^{4}`) whilst the label string is amended to read :math:`y [\times 10^{-4}]` by setting the units label to :math:`[ \times 10^{-4}]`. Changing the axis label to something like :math:`x` :math:`[ \times 10^{4} ]` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:changingunits`. .. _sec:timeunits: Changing the time units ~~~~~~~~~~~~~~~~~~~~~~~~ Units for the time used in the legend can be changed using the ``change physical unit settings`` in the :ref:`sec:menu-d`. Changing the units of column zero corresponds to the time (appears as the first row in the ‘splash.units’ file). .. _sec:menu-i: (i)nteractive mode ------------------ .. image:: figs/menu-i.png :width: 50.0% The menu option i) turns on/off :ref:`sec:interactive`. With this option turned on (the default) and an appropriate device selected (i.e., the X-window, not /png or /ps), after each plot the program waits for specific commands from the user. With the cursor positioned anywhere in the plot window (but not outside it!), many different commands can be invoked. Some functions you may find useful are: Move through timesteps by pressing ``space`` (``b`` to go back); zoom/select particles by selecting an area with the mouse; rotate the particles by using the :math:`<`, :math:`>`,[, ] and :math:`\backslash`, / keys; log the axes by holding the cursor over the appropriate axis and pressing the ``l`` key. Press ``q`` in the plot window to quit :ref:`sec:interactive`. A full list of these commands is obtained by holding the cursor in the plot window and pressing the ‘h’ key (h for help). .. hint:: Changes made in :ref:`sec:interactive` will only be saved by pressing the ‘s’ (for save) key. Otherwise pressing ``space`` (to advance to the next timestep) erases the changes made during :ref:`sec:interactive`. A more limited :ref:`sec:interactive` applies when there is more than one plot per page. Many more commands could be added to the :ref:`sec:interactive`, limited only by your imagination. Please send me your suggestions! Adapting the plot limits ~~~~~~~~~~~~~~~~~~~~~~~~~ Press ``a`` in :ref:`sec:interactive` to adapt the plot limits to the current minimum and maximum of the quantity being plotted. With the mouse over the colour bar, this applies to the colour bar limits. Also works even when the page is subdivided into panels. To adapt the size of the arrows on :ref:`sec:vectorplots`, press ``w``. To use “adaptive plot limits” (where the limits change at every timestep), see :ref:`sec:adapt`. Making the axes logarithmic ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Press ``l`` in :ref:`sec:interactive` with the mouse over either the x or y axis or the colour bar to use a logarithmic axis. Pressing ``l`` again changes back to linear axes. To use logarithmic labels as well as logarithmic axes, see :ref:`sec:loglabels`. Cycling through data columns interactively ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Use ``f`` in :ref:`sec:interactive` on :ref:`sec:renderplot` to interactively ‘flip’ forwards to the next quantity in the data columns (e.g. thermal energy instead of density). Use ’F’ to flip backwards. .. _sec:colourparts: Colouring a subset of the particles and retaining this colour through other timesteps ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. figure:: figs/colourparts.pdf :alt: coloured particles :name: fig:colourparts :width: 80.0% Example of particles coloured interactively using the mouse (left) and selection using a parameter range (right), which is the same as the plot on the left but showing only particles in a particular density range (after an intermediate plot of density vs x on which I selected a subset of particles and hit ``p``) In :ref:`sec:interactive`, select a subset of the particles using the mouse (that is left click and resize the box until it contains the region you require), then press either 1-9 to colour the selected particles with colours corresponding to plotting library colour indices 1-9, press ``p`` to plot only those particles selected (hiding all other particles), or ``h`` to hide the selected particles. An example is shown in the left panel of :numref:`fig:colourparts`. Particles retain these colours between timesteps and even between plots. This feature can therefore be used to find particles within a certain parameter range (e.g. by plotting density with x, selecting/colouring particles in a given density range, then plotting x vs y in which the particles will appear as previously selected/coloured). An example of this feature is shown in the right panel of :numref:`fig:colourparts` where I have plotted an intermediate plot of density vs x on which I selected a subset of particles and hit ``p`` (to plot only that subset), then re-plotted x vs y with the new particle selections. To “un-hide” or “de-colour” particles, simply select the entire plotting area and press ``1`` to restore all particles to the foreground colour index. Particles hidden in this manner are also no longer used in the rendering calculation. Thus it is possible to render using only a subset of the particles (e.g. using only half of a box, or only high density particles). An example is shown in :numref:`fig:rendersubset`. To colour the particles according to the value of a particular quantity, see :ref:`sec:colournotrender`. .. important:: Selection in this way is based on the particle *identity*, meaning that the parameter range itself is not preserved for subsequent timesteps, but rather the subset of particles selected from the initial timestep. This can be useful for working out which particles formed a particular object in a simulation by selecting only particles in that object at the end time, and moving backwards through timesteps retaining that selection. Working out which particles formed a particular object in a simulation ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This can be achieved by selecting and colouring particles at a particular timestep and plotting the same selection at an earlier time. See :ref:`sec:colourparts` for details. Plotting only a subset of the particles ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ To turn plotting of certain particle *types* on and off, see :ref:`sec:plotparticlesbytype`. To select a subset of the particles based on restrictions of a particular parameter or by spatial region see :ref:`sec:colourparts`. .. _sec:rendersubset: Rendering using only a subset of the particles ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Particles can be selected and ‘hidden’ interactively (see :ref:`sec:colourparts`) – for :ref:`sec:renderplot` ‘hidden’ particles are also not used in the interpolation calculation from the particles to the pixel array. An example is shown in :numref:`fig:rendersubset`, where I have taken one of the rendered examples in :ref:`sec:basic`, selected half of the domain with the mouse and pressed ’p’ to plot only the selected particles. The result is the plot shown. .. figure:: figs/rendersubset.pdf :alt: rendering with subset of particles :name: fig:rendersubset :width: 50.0% Example of :ref:`sec:renderplot` using only a subset of the particles. Here I have selected only particles on the right hand side of the plot using the mouse and hit ’p’ to plot only those particles. .. important:: Selection of data subsets is by default based on *particle identity* – the same particles will be used for the plot in subsequent dumps, allowing one to easily track the Lagrangian evolution of a patch of gas. See :ref:`sec:rangerestrict` to select by fixed parameter ranges (e.g. to only show particles in fixed density range). .. hint:: A range restriction can be set in :ref:`sec:interactive` by selecting the restricted box using the mouse and pressing ``x``, ``y`` or ``r`` to restrict the particles used to the x, y (or r for both x and y) range of the selected box respectively. Pressing ``S`` at the main menu will save such range restrictions to the ``splash.limits`` file. Tracking a set of particles through multiple timesteps ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:rendersubset`. .. _sec:obliquexsec: Taking an oblique cross section interactively ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ It is possible to take an oblique :ref:`sec:xsec` through 3D data using a combination of rotation and :ref:`sec:xsec` slice plotting. To set the position interactively, press ``x`` in :ref:`sec:interactive` to draw the position of the :ref:`sec:xsec` line (e.g. on an x-y plot this then produces a z-x plot with the appropriate amount of rotation to give the cross section slice in the position selected). .. hint:: Interactively selecting a :ref:`sec:xsec` will work even if the current plot is a 3D column integrated projection. In this case the setting ``projection or cross section`` changes to ``cross section`` in order to plot the slice. .. _sec:menu-p: (p)age options -------------- .. image:: figs/menu-p.png :width: 50.0% Options related to the page setup are changed in the p)age submenu. .. _sec:nstepsontopofeachother: Overlaying timesteps/multiple dump files on top of each other ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ It is possible to over-plot data from one file on top of data from another using the ``plot n steps on top of each other`` option from the :ref:`sec:menu-p`. Setting :math:`n` to a number greater than one means that the page is not changed until :math:`n` steps have been plotted. Following the prompts, it is possible to change the colour of all particles between steps and the graph markers used and plot an associated legend (see below). .. hint:: This option can also be used in combination with a multiplot (see :ref:`sec:multiplot`) – for example plotting the density vs x and pressure vs x in separate panels, then with :math:`n > 1` all timesteps will be plotted in *each* panel. When more than one timestep is plotted per page with different markers/colours, an additional legend can be plotted (turn this on in the :ref:`sec:menu-g`, or when prompted while setting the ``plot n steps on top of each other`` option). The text for this legend is just the filename by default, if one timestep per file, or just something dull like ’step 1’, if more than one timestep per file. .. hint:: To change the legend text, create a file called ``splash.legend`` in the working directory, with one label per line. The position of the legend can be changed either manually via the ``legend and title options`` in the :ref:`sec:menu-p`, or by positioning the mouse in :ref:`sec:interactive` and pressing ``G`` (similar keys apply for moving plot titles and the legend for :ref:`sec:vectorplots` – press ``h`` in :ref:`sec:interactive` for a full list). Plotting results from multiple files in the same panel ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:nstepsontopofeachother`. Plotting more than one dump file on the same page ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This is slightly different to “plotting more than one dump file on the same panel” .. _sec:axessettings: Changing axes settings ~~~~~~~~~~~~~~~~~~~~~~~ Axes settings can be changed in the :ref:`sec:menu-p`, by choosing ``axes options``. The options are as follows: :: -4 : draw box and major tick marks only; -3 : draw box and tick marks (major and minor) only; -2 : draw no box, axes or labels; -1 : draw box only; 0 : draw box and label it with coordinates; 1 : same as AXIS=0, but also draw the coordinate axes (X=0, Y=0); 2 : same as AXIS=1, but also draw grid lines at major increments of the coordinates; 3 : draw box, ticks and numbers but no axes labels; 4 : same as AXIS=0, but with a second y-axis scaled and labelled differently 10 : draw box and label X-axis logarithmically; 20 : draw box and label Y-axis logarithmically; 30 : draw box and label both axes logarithmically. Turning axes off ~~~~~~~~~~~~~~~~~ Plot axes can be turned off by choosing ``axes options`` in the :ref:`sec:menu-p` or by deleting them using the backspace key in :ref:`sec:interactive`. See :ref:`sec:axessettings` for more details. Turning axes labels off ~~~~~~~~~~~~~~~~~~~~~~~~ Axes labels and numbering can be turned off via the ``axes options`` option in the :ref:`sec:menu-p` or by deleting them using the backspace key in :ref:`sec:interactive`. See :ref:`sec:axessettings` for more details. .. _sec:loglabels: Using logarithmic axes labels ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Logarithmic axes (that is where the quantity plotted is logged) can be set via the ``apply log or inverse transformations`` option in the :ref:`sec:menu-l` or simply by pressing ``l`` with the cursor over the desired axis (or the colour bar) in :ref:`sec:interactive`. By default the axes labels reads :math:`log(x)` and the number next to the axis is :math:`-4` when :math:`x` is 10\ :math:`^{-4}`. Logarithmic axes labels (i.e., where the label reads :math:`x` and the number next to the axis is :math:`10^{-4}` with a logarithmic scale) can be specified by choosing the ``axes options`` option in the :ref:`sec:menu-p` and setting the axes option to 10, 20 or 30 as necessary (see :ref:`sec:axessettings` for more details). Plotting a second, rescaled y-axis on the right hand side of a plot ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A second y axis can be added by selecting the axis=4 option in the ``axes option`` in the :ref:`sec:menu-p` (see :ref:`sec:axessettings`). This will prompt for the scaling and alternative label: :: enter axis option ([-4:30], default=0): 4 enter scale factor for alternative y axis ([0.000:], default=1.000): 10.0 enter label for alternative y axis (default=""): y [other units] .. _sec:papersize: Changing the size of the plotting surface ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The physical size of the viewing surface used for plotting can be changed via the ``change paper size`` option in the :ref:`sec:menu-p`. This affects the size of the X-window (if plotted to the screen) and the size of .png or images generated (if plotted to these devices). Several preset options are provided or the paper size in x and y can be explicitly specified in inches or pixels. .. _sec:nacrossndown: Dividing the plotting page into panels ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The plotting page can be divided into panels using the ``subdivide page into panels`` option in the :ref:`sec:menu-p`. For multiple plots per page (i.e., nacross :math:`\times` ndown :math:`> 1`) a more limited :ref:`sec:interactive` applies (basically because the data used for the plots is no longer stored in memory if there is more than one plot on the same page meaning that functionality such as selecting particles must be turned off). .. _sec:tiling: Tiling plots with the same :math:`x-` and :math:`y-` axes ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Plots with the same :math:`x-` and :math:`y-` axes are tiled if the tiling option from the :ref:`sec:menu-p`. Tiling means that only one axis is shown where multiple plots share the same x or y axis and that the plots are placed as close to each other as possible. For :ref:`sec:renderplot` a shared colour bar is plotted which spans the full length of the page. .. _sec:squarexy: Using non-proportional scales for spatial dimensions ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ By default if the x and y axes are both spatial coordinates, the axes are scaled proportionately. This can be changed via the ``spatial dimensions have same scale`` option in :ref:`sec:menu-p`. Using non-square axes on coordinate plots ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:squarexy`. Changing the character height for axes, labels and legends ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The character height used for axes, labels and legends can be changed via the :ref:`sec:menu-p`. The character height is relative to the paper size where 1.0 = 1/40th of the page height. The page height can be changed in :ref:`sec:papersize`. Using a thicker line width on plots ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The line width used for axes and text can be changed via the :ref:`sec:menu-p`. .. _sec:pagecolours: Changing the foreground and background colours ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The background and foreground colour of a plot can be changed via the ``set foreground/background colours`` option in the :ref:`sec:menu-p`. Note that the background colour setting has no effect on postscript devices (see :ref:`sec:postscript` for more details). Plotting axes, legends and titles in white even when the labels are plotted in black ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ By default, axes, legends and titles are plotted in the foreground colour (e.g. black). However if the plot itself is also largely black (e.g. :ref:`sec:renderplot` when lots of particles are plotted) it can be useful to overplot those parts of the axes and labelling which lie on top of the plotting surface in the background colour (e.g. white). A prompt for this is given when setting the ``set foreground/background colours`` option in the :ref:`sec:menu-p`. The prompt appears as follows: :: ---------------- page setup options ------------------- ... 9) set foreground/background colours enter option ([0:8], default=0):9 Enter background colour (by name, e.g. "black") (default=""):white Enter foreground colour (by name, e.g. "white") (default=""):black Overlaid (that is, drawn inside the plot borders) axis ticks, legend text and titles are by default plotted in the foreground colour [i.e., black]. Do you want to plot these in background colour [i.e., white] instead ? (default=no):y In the above I have selected a background colour of white, a foreground colour of black. Answering yes to the last question means that those parts of the axes which lie on top of the viewing surface (and any labels) will be plotted in white (the background colour) instead of the foreground colour (black). .. _sec:menu-g: le(g)end and title options -------------------------- .. image:: figs/menu-g.png :width: 50.0% .. _sec:title: Adding titles to plots / repositioning titles ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Plots may be titled individually by creating a file called ``splash.titles`` in the current directory, with the title on each line corresponding to the position of the plot on the page. Thus the title is the same between timesteps unless the steps are plotted together on the same physical page. Leave blank lines for plots without titles. For example, creating a file called ``splash.titles`` in the current directory, containing the text: :: plot one plot two plot three and positioning the title using the default options, will produce a plot with one of these titles on each panel. .. _sec:legendoff: Turning off/moving the time legend ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The position of the time legend can be set interactively by positioning the mouse in the plot window and pressing ’G’. To set the position non-interactively and/or change additional settings such as the justification, use the ``time legend on/off/settings`` option in the :ref:`sec:menu-g`. .. _sec:timelegendtext: Changing the text in the time legend ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The text which appears the time legend (by default this is ``t=``) can be changed via the ``time legend on/off/settings`` option in the :ref:`sec:menu-g`. To rescale the *value* of the time displayed in the time legend (default value is as read from the dump file), see :ref:`sec:timeunits`. Making the legend read 'z=' instead of 't=' ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:timelegendtext`. An option to change the legend text is provided in the ``time legend on/off/settings`` option in :ref:`sec:menu-g`. The numeric value of the time legend is as read into the ``time`` array in the read_data routine. This value can be rescaled by setting a unit for time (see :ref:`sec:timeunits`). Plotting the time legend on the first row/column of panels / nth panel only ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ An option to plot the time legend on the first row or column of panels or on a single panel only appears in the :ref:`sec:menu-g`. Plotting a length scale on coordinate plots ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ An option to plot a length scale (i.e., ``|---|`` with a label below it indicating the length) on coordinate plots (i.e., plots where both :math:`x-` and :math:`y-`\ axes refer to particle coordinates) is provided in the :ref:`sec:menu-g`. Annotating a plot with squares, rectangles, arrows, circles and text ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Use the ``annotate plot`` option in :ref:`sec:menu-g` to annotate plots with a range of geometric objects (squares, rectangles, arrows, circles and text) with full control over attributes such as line width, line style, colour, angle and fill style. Text annotation can also be added/deleted in :ref:`sec:interactive` using ``ctrl-t`` (to add) and the backspace key (to delete). Text can also be added to plots by adding titles (:ref:`sec:title`) which can be different in different panels. Text labels added using shape annotation differ from titles by the fact that they must appear the same in each panel and are positioned according to the world co-ordinates of the plot (rather than relative to the viewport). Shape text can also be displayed at arbitrary angles. An option to plot length scales (``|---|``) on coordinate plots is implemented separately via the ``plot scale on coordinate plots`` option in :ref:`sec:menu-g`. Adding your name to a plot/movie ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Arbitrary text annotation can be added/removed in :ref:`sec:interactive` using ``ctrl-t`` (to add) and the backspace key (to delete) or via the ``annotate plot`` option in the :ref:`sec:menu-g`. .. _sec:menu-o: particle plot (o)ptions ----------------------- .. image:: figs/menu-o.png :width: 50.0% The following are tasks which can be achieved via options in the :ref:`sec:menu-o`. .. _sec:plotparticlesbytype: Plotting non-gas particles (e.g. ghosts, boundary, sink particles) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Particles of different types can be turned on or off (i.e., plotted or not) using the ``turn on/off particles by type`` option in :ref:`sec:menu-o`. This option also prompts to allow particles of non-SPH types to be plotted on top of :ref:`sec:renderplot` (useful for sink or star particles - this option does not apply to SPH particle types). Turning SPH particle types on or off also determines whether or not they will be used in the rendering calculation (i.e., the interpolation to pixels). This particularly applies to ghost particles, where ghost particles will only be used in the rendering if they are turned on via this menu option. (The fact that particles of a given type are SPH particles or not is specified by the ``UseTypeInRendering`` flags in the set_labels part of the read_data file). Plotting non-gas particles on top of rendered plots ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ An option to plot non-SPH particles on top of :ref:`sec:renderplot` (e.g. sink particles) can be set when turning particle types on/off via the ``turn on/off particles by type`` option in :ref:`sec:menu-o` (see :ref:`sec:plotparticlesbytype`). Using ghost particles in the rendering ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:plotparticlesbytype`. Turn off plotting of gas particles ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Particles can be turned on or off by type via the ``turn on/off particles by type`` option in :ref:`sec:menu-o`. See :ref:`sec:plotparticlesbytype`. .. _sec:darkmatter: Plotting dark matter particles ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ To plot dark matter particles (e.g. for the gadget read) the particle type corresponding to dark matter particles must be turned on via the ``turn on/off particles by type`` option in :ref:`sec:menu-o`. Turning this option on means that dark matter particles will appear on particle plots. To make :ref:`sec:renderplot` of dark matter (e.g. showing column density), it is necessary to define smoothing lengths and a fake “density” for the dark matter particles. If your data read already supplies individual smoothing lengths for dark matter particles, the only thing to do is define a fake density field with a constant value (e.g. :math:`\rho = 1` for all dark matter particles). The actual density value does not matter, so long as it is non-zero, as the rendering for density does not use it unless the ``normalise interpolations`` option in the :ref:`sec:menu-r` is set (which it is not by default). This is because SPLASH constructs the weight: .. math:: w_{part} = \frac{m_{part}}{\rho_{part} h_{part}^{\nu}}, (see `Price 2007 `_) and then interpolates for any quantity A using .. math:: A_{pixels} = \sum_{part} w_{part} A_{part} W_{kernel}, so if :math:`A = \rho` then the actual rho value cancels. For the GADGET data read you can define the smoothing length for dark matter particles by setting the environment variable GSPLASH_DARKMATTER_HSOFT (see :ref:`sec:gsplash` for details), which also triggers the creation of a fake density column as required. With this variable set dark matter particles are treated identically to SPH particles and can be rendered as usual (although the only meaningful quantity to render is the density). A much better way is to define smoothing lengths individually for dark matter particles, for example based on a local number density estimate from the relation .. math:: h \propto n^{-1/3}, \hspace{0.5cm} \textrm{where} \hspace{0.5cm} n_{i} = \sum_{j} W_{ij}. Actually, none of this should be necessary, as the gravity for dark matter should be softened with smoothing lengths defined like this in the first place. The historical practice of fixed softening lengths has arisen only because of confusion about what softening really means (and worries about energy conservation with adaptive softening lengths). What you are trying to do is solve Poisson’s equation for the dark matter density field, defined with a kernel density estimate and using fixed softening lengths is not a way to get a good density... but don’t get me started, read [PM07]_ instead. .. danger:: For simulations using both SPH and dark matter particles, dark matter particles will contribute (incorrectly) to the SPH rendering when the environment variable is set and the plotting of dark matter particles is turned on. Thus to plot just gas column density in this case, dark matter particles must be turned off [via the :ref:`sec:menu-o`], and similarly to plot just dark matter density if both SPH and dark matter particles are present, SPH particles must be turned off. Plotting a column density plot of dark matter/N-body particles ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:darkmatter`. .. _sec:plotsinks: Plotting sink particles ~~~~~~~~~~~~~~~~~~~~~~~~ Sink particles will be plotted on particle plots once turned on via the ``turn on/off particles by type`` option in :ref:`sec:menu-o`. Setting this option also gives a prompt for whether or not to plot sink particles on top of :ref:`sec:renderplot` (to which the answer should be yes). See :ref:`sec:plotparticlesbytype` for more details. To plot sink particles as a circle scaled to the sink radius, select the appropriate marker type (32-35) in the ``change graph markers for each type`` option in :ref:`sec:menu-o`. This allows plotting of particles of a given type with circles, filled or open, proportional to their smoothing lengths. Thus, the smoothing length for sink particles needs to be set to their accretion radius (or at least proportional to it). .. hint:: A good option for sink particles is to print “outlined” filled circles (marker 34) — these show up on both black or white backgrounds. Plotting sink particles with size proportional to the sink radius ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:plotsinks`. Plotting a point mass particle with physical size ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:plotsinks`. Changing graph markers for each particle type ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The graph markers used to plot each particle type can be changed via the ``change graph markers for each type`` option in the :ref:`sec:menu-o`. The full list of available markers is given in the documentation for giza (also similar to the markers used in pgplot). SPLASH also allows the particles to be marked by a circle proportional to the smoothing length for that particle, implemented as marker types 32-35 under the ``change graph markers for each type`` option in the :ref:`sec:menu-o`. .. _sec:partcolours: Plotting each particle type in a different colour ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Each particle type can be plotted in a different colour via the ``set colour for each particle type`` option in the :ref:`sec:menu-o`. Changing the order in which different particle types are plotted ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The order in which particle types are plotted can be changed via the ``change plotting order of types`` option in :ref:`sec:menu-o`. For example, it is possible to make dark matter particles be plotted on top of gas particles rather than the default which is vice-versa. This is only implemented for particle types which are stored contiguously (one after the other) in the data read, rather than mixed in with each other. .. _sec:lines: Plotting using lines instead of dots (e.g. for energy vs time plots) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ An option to plot a line joining all of the points on a plot can be set via the ``plot line joining particles`` option in :ref:`sec:menu-o`. When set, this option plots a line connecting the (gas only) particles in the order that they appear in the data array. Useful mainly in one dimension or when plotting ascii data, although can give an indication of the relative closeness of the particles in memory and in physical space in higher dimensions. The line colours and styles can be changed. To plot the line only with no particles, turn off gas particles using the ``turn on/off particles by type option`` from :ref:`sec:menu-o`. Plotting multiple lines with different colours/line styles and a legend ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ When multiple timesteps are plotted on the same physical page, the line style can be changed instead of the colour (this occurs when the change colour option is chosen for multiple steps per page – see the ``change plots per page`` option in the :ref:`sec:menu-p`. Joining the dots ~~~~~~~~~~~~~~~~~ See :ref:`sec:lines`. .. _sec:smoothingcircle: Plotting the size of the smoothing circle around selected particles ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ On coordinate plots this option plots a circle of radius :math:`2h` around selected particles. This is primarily useful in debugging neighbour finding routines. Where only one of the axes is a coordinate this function plots an error bar of length :math:`2h` in either direction is plotted in the direction of the coordinate axis. See also :ref:`sec:findingaparticle` for more details. .. _sec:findingaparticle: Locating a particular particle in the data set ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The best way to locate a particular particle in the data set is to use the ``plot smoothing circles`` option in :ref:`sec:menu-o`, e.g: :: Please enter your selection now (y axis or option):o5 ------------- particle plot options ------------------- Note that circles of interaction can also be set interactively Enter number of circles to draw ([0:100], default=0):1 Enter particle number to plot circle around ([1:959], default=1): 868 then upon plotting a coordinate plot (e.g. x vs y), particle 868 will be plotted with a circle of size :math:`2h` which makes it easy to distinguish from the other particles. See also :ref:`sec:smoothingcircle`. .. _sec:geom: Plotting in different coordinate systems (e.g. cylindrical coordinates) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The coordinates of position and of all vector components can be transformed into non-cartesian coordinate systems using the ``change coordinate system`` option in :ref:`sec:menu-o`. For example, a dump file with columns as follows: :: ------------------------------------------------------- 1) x 6) log density 2) y 7) v\dx 3) z 8) v\dy 4) particle mass 9) v\dz 5) h ------------------------------------------------------- 10) multiplot [ 4 ] m) set multiplot ------------------------------------------------------- Please enter your selection now (y axis or option): choosing :ref:`sec:menu-o`, option 7) and choosing cylindrical coordinates then produces; :: You may choose from a delectable sample of plots ------------------------------------------------------- 1) r 6) log density 2) phi 7) v\dr 3) z 8) v\dphi 4) particle mass 9) v\dz 5) h ------------------------------------------------------- ... transforming both coordinates and vectors into the chosen coordinate system. .. hint:: :ref:`sec:renderplot` are also possible in coordinate systems other than those native to the file. .. hint:: For 3D SPH simulations, extra columns will appear in the menu in cylindrical or spherical coordinates allowing plots of azimuthally-averaged surface density and Toomre Q parameter. For more details see :ref:`sec:surfdens`. Details of the coordinate transformations are given in :ref:`sec:coordtransforms`. If you have a coordinate system you would like implemented, please email me the details! Plotting vector components in different coordinate systems ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:geom`. Plotting orbital velocities ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:geom`. Plotting against azimuthal angle/cylindrical radius/etc ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:geom`. .. _sec:exactsolns: Plotting the exact solution to common test problems ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Turn on `plot exact solution` in :ref:`sec:menu-o` The following exact solutions are provided - Any arbitrary function y = f(x,t) (can be plotted on any or all of the plots). The functions to be plotted can also be specified by creating a ``splash.func`` file with one function per line. - Hydrodynamic shock tubes (Riemann problem) – a full solution is provided for all types of waves propagating in either direction. - Spherically-symmetric 3D sedov blast wave problem. - Polytropes (with arbitrary :math:`\gamma`) - One and two dimensional toy stars. This is a particularly simple test problem for SPH codes described in [MP04]_. - Linear wave. This simply plots a sine wave of a specified amplitude, period and wavelength on the plot specified. - MHD shock tubes (tabulated). These are tabulated solutions for 7 specific MHD shock tube problems. - h vs :math:`\rho`. This is the exact solution relating smoothing length and density in the form :math:`h \propto (m/\rho)^{1/\nu}` where :math:`\nu` is the number of spatial dimensions. - radial density profiles. For various models commonly used in :math:`N-`\ body simulations. - Exact solution from a file. This option reads in an exact solution from the filename input by the user, assuming the file contains two columns containing the :math:`x-` and :math:`y-` coordinates of an exact solution to be plotted as a line on the plot specified. Details of the calculation of the exact solutions are given in :ref:`sec:exact`. An example plot using the Sedov blast wave exact solution is shown in :numref:`fig:sedov`. .. figure:: figs/sedov_example.png :alt: sedov exact solution :name: fig:sedov :width: 50.0% Example of a plot utilising the Sedov blast wave exact solution. Taken from [RP07]_. Plotting an exact solution from a file ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:exactsolns`. One of the options for exact solution plotting is to read the exact solution from either one or a sequence of ascii files, such that the results are plotted alongside the particle data. The filename(s) can be specified by the user and will be saved to the ‘splash.defaults’ file so that the solution(s) will be read and plotted on subsequent invocations of splash . Changing the exact solution line style & colour ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The line style and colour of the exact solution line can be changed via the ``exact solution plot options`` option in :ref:`sec:menu-o`. This option can also be used to turn on/off calculation of various error norms together with an inset plot of the residual error on the particles. See :ref:`sec:exact` for details of the error norms calculated. Setting the number of points used in an exact solution calculation ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The number of points used in an exact solution calculation can be changed via the ``exact solution plot options`` option in :ref:`sec:menu-o`. Plotting an inset plot of residual errors from an exact solution ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ An inset plot of residual errors between the plotted points and an exact solution calculation can be turned on via the ``exact solution plot options`` option in :ref:`sec:menu-o`. .. _sec:menu-l: (l)imits menu ------------- .. image:: figs/menu-l.png :width: 50.0% .. _sec:adapt: Using plot limits which adapt automatically for each new plot ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Adaptive plot limits can be set using option 1 of the :ref:`sec:menu-l`. Different settings can be applied to coordinate axes and non-coordinate axes. Changing plot limits interactively and pressing ``s`` in :ref:`sec:interactive` will change this option back to using fixed limits. Using adaptive plot limits for the colour bar but not for the coordinates ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Adaptive plot limits can be set individually for coordinate axes and non-coordinate axes (e.g. the colour bar) via the ``use adaptive/fixed limits`` option in the :ref:`sec:menu-l`. See :ref:`sec:adapt`. Setting plot limits manually ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Plot limits can be set manually using option 2) of the :ref:`sec:menu-l` (or simply ``l2`` from the main menu). Alternatively you can edit the ``splash.limits`` file created by :ref:`sec:menu-s` prior to invoking splash (this file simply contains the minimum and maximum limits for each column on consecutive lines). .. _sec:track: Making plot limits relative to a particular particle ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Particle tracking limits (i.e., where a chosen particle is always at the centre of the plot and limits are set relative to that position) can be set via the ``make xy limits relative to particle`` option in the :ref:`sec:menu-l`. Alternatively particle tracking limits can be set interactively by pressing ``t`` in :ref:`sec:interactive` with the cursor over the particle you wish to track. .. warning:: This option only works if particle identities are preserved between timesteps in the data files .. important:: With particle tracking limits set, the radius calculated via the ``calculate extra quantities`` option in the :ref:`sec:menu-d` is calculated relative to the tracked particle. Centreing on a sink particle can also be achieved using the SPLASH_CENTRE_ON_SINK environment variable (see :ref:`sec:envvariables`). Plotting in a comoving reference frame ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A co-moving reference frame can be set using the ``make xy limits relative to particle`` option in the :ref:`sec:menu-l`. Coordinate limits are then centred on the selected particle for all timesteps, with offsets as input by the user. This effectively gives the ‘Lagrangian’ perspective. See :ref:`sec:track` for more details. Centreing on a sink particle can also be achieved using the SPLASH_CENTRE_ON_SINK environment variable. Setting the origin to correspond to a particular particle ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:track`. Tracking a particle ~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:track`. .. _sec:tracksink: Setting the origin to the position of the :math:`n`\ th sink particle ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This can be achieved using the ``make xy limits relative to particle`` option in the :ref:`sec:menu-l`. For example, to track the first sink particle we would proceed as follows: :: Please enter your selection now (y axis or option):l3 ------------------ limits options --------------------- To track particle 4923, enter 4923 To track the 43rd particle of type 3, enter 3:43 Enter particle to track: (default="0"): 3:1 where 3:1 indicates the first particle of type 3. The origin is set to the position of this particle and limits are relative to its position. See :ref:`sec:track` for more details. Plotting radial plots around sink particles ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ First, set the origin to the location of the sink, as described above. Then simply change to spherical coordinates using the ``change coordinate systems`` option in :ref:`sec:menu-o`. Alternatively, compute the radius using the ``calculate extra quantities`` option in the :ref:`sec:menu-d`. Automatically adapting plot limits to match aspect ratio of output device ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ An option to automatically adjust the plot limits to match the aspect ratio of the output device is given in the :ref:`sec:menu-l`, and is also prompted for whenever the paper size is changed (via the ``change paper size`` option in the :ref:`sec:menu-p`, see :ref:`sec:papersize`). Plotting with log axes. ~~~~~~~~~~~~~~~~~~~~~~~~ Log axes can be set either interactively (by pressing ``l`` with the cursor over the desired axis) or manually via the ``apply log or inverse transformations to columns`` option in the :ref:`sec:menu-l`. To use logarithmic axes labels as well, see :ref:`sec:loglabels`. Plotting the square root, inverse or square of a quantity ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Columns can be logged, inverted, sqrt-ed, squared or any combination of the above via the ``apply log or inverse transformations to columns`` option in the :ref:`sec:menu-l`. If you have any additional transformations you would find useful please let me know, as it is straightforward to add more. .. _sec:resetlimits: Resetting limits for all columns ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Limits for all columns can be reset to their minimum and maximum values from the current dump file via the ``reset limits for all columns`` option in the :ref:`sec:menu-l`. See :ref:`sec:interactive` for details of resetting plot limits for a particular plot interactively. Restoring all plot limits to their minimum and maximum values in the current dump file ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:resetlimits`. .. _sec:rangerestrict: Using a subset of data restricted by parameter range ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ You can use only a subset of the particles in both particle plots and :ref:`sec:renderplot`, according to restrictions on any or all of the data columns (for example, using only particles with :math:`\rho > 10`, in the 3D box :math:`x,y,z \in [-0.1, 0.1]`). Whilst this has always been possible by selecting, colouring and/or hiding particles in :ref:`sec:interactive` (see :ref:`sec:rendersubset`), the difference here is that the selection is based, for each timestep, strictly on the parameter range, rather than being a selection based on particle identity. This means that the parameter range is also saved to the ``splash.limits`` (i.e., by :ref:`sec:menu-s`) and is shown when splash launches via lines such as: :: >> current range restrictions set: ( 1.693E-01 < x < 1.820E-01 ) ( 2.205E-01 < y < 2.265E-01 ) ( 7.580E-06 < density < 2.989E-05 ) >> only particles within this range will be plotted and/or used in interpolation routines or more usually: :: >> no current parameter range restrictions set Parameter range restrictions can be set either manually via the :ref:`sec:menu-l` (option 7) or interactively by selecting a region in the plot and pressing ‘x’, ‘y’ or ‘r’ to restrict using the :math:`x`, :math:`y` or both :math:`x` and :math:`y` limits of the selected area respectively (pressing ‘R’ instead removes all currently set restrictions). Another way of setting manual range restrictions is simply to edit the ``splash.limits`` file directly (this simply contains the min and max limits for each column, followed optionally by a third and fourth column specifying, respectively, the min and max of the range restriction). Plotting only particles with :math:`\rho > 10`, :math:`u > 20` and :math:`-0.25 < x < 0.25` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Plotting a subset of the particles restricted by a parameter can be achieved by setting a parameter range restriction (which does not change between timesteps – see :ref:`sec:rangerestrict`), or alternatively by an interactive selection based on particle identity (see :ref:`sec:rendersubset`). .. _sec:menu-r: (r)endering options ------------------- .. image:: figs/menu-r.png :width: 50.0% Changing the number of pixels in a rendered image ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The number of pixels in a rendered image can be set manually using the :ref:`sec:menu-r`, option 1 (or simply type ``r1`` from the main menu). The number set is the number of pixels along the :math:`x-`\ axis. The number of pixels along the :math:`y-`\ axis is determined by the aspect ratio of the plot. The number of pixels used in an image is, by default, automatically determined by the actual number of pixels available on the graphics device, which depends in turn on the size of the page (the page size can be set manually in the :ref:`sec:menu-p` – see :ref:`sec:papersize`). For vector (non-pixel) devices such as postscript, svg or pdf, the number of pixels is set to :math:`1024/\textrm{n}`, where n is the number of panels across the page. Changing the colour scheme ~~~~~~~~~~~~~~~~~~~~~~~~~~~ The colour scheme used for :ref:`sec:renderplot` can be changed either by pressing ``m`` or ``M`` in :ref:`sec:interactive` to cycle through the available schemes or manually by using the ``change colour scheme`` option in the :ref:`sec:menu-r`. A demonstration of all the colour schemes can be also be invoked from this menu option. Setting the colour scheme to zero plots only the contours of the rendered quantity (assuming that plot contours is set to true). The colour schemes available are shown in :numref:`fig:colourschemes`. .. figure:: figs/colourschemes.pdf :alt: splash colour schemes :name: fig:colourschemes splash colour schemes User contributed colour schemes are eagerly invited (just send me either: a table of r,g,b colour indices [if you know them] or just an image of a colour bar you wish to reproduce and I will add it). Plotting contours as well as the rendered image ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Contours of either the rendered pixel array or of another (separate) quantity can be plotted on top of :ref:`sec:renderplot` by setting the ``plot contours`` option from the :ref:`sec:menu-r`. With this option set, an extra prompt will appear after the render prompt asking the user for a quantity to be contoured. The contoured quantity can also be set via the command line options (:ref:`sec:commandline`). If the rendered and contoured quantities are the same, further prompts appear which enable the limits for the contour plot to be set separately to the render plot. These limits are also saved separately in the ``splash.limits`` file when written. .. hint:: To plot contours *instead* of the rendered image, use the ``change colour scheme`` option from the :ref:`sec:menu-r` and choose colour scheme 0 (contours only). Plotting contours instead of a rendered image ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ To plot contours instead of the rendered image, use the ``change colour scheme`` option from the :ref:`sec:menu-r` and choose colour scheme 0 (contours only). Changing the number of contour levels ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The number of contour levels used whenever contours are drawn can be set via the ``change number of contours`` option in the :ref:`sec:menu-r`. The contour levels can also be manually specified (see :ref:`sec:contoursmanual`). .. _sec:contoursmanual: Setting the contour levels manually ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ As of v1.15.0, contour levels can be set manually by creating a file called ``splash.contours`` in the current directory (or ``prefix.contours`` if the ``splash -p prefix`` is specified on the command line). This file should contain one contour level per line, optionally with a label for each contour, e.g. :: 1.e-2 level 1 1.e-1 level 2 0.1 my really great contour 1.0 hi mum Adding numeric labels to contours ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ An option to write numeric labels on contours appears as part of the ``change number of contours`` option in the :ref:`sec:menu-r`. Adding arbitrary contour labels ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Contours can also be labelled manually by creating a ``splash.contours`` file. See :ref:`sec:contoursmanual`. Turning the colour bar off/ moving the colour bar label ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The colour bar can be turned on or off and the style chosen (e.g. horizontal vs vertical) and for the vertical bar, the label moved closer to the bar itself, via the ``colour bar options`` option in the :ref:`sec:menu-r`. To change the text in the colour bar label, see :ref:`sec:setprojlabel`. .. _sec:colourbarstyle: Changing the style of the colour bar ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The colour bar style (i.e., vertical vs. horizontal, plot-hugging vs. non plot-hugging, one-sided vs. two-sided, floating vs. fixed) can be changed via the ``colour bar options`` option in the :ref:`sec:menu-r`. If you want a different style implemented, email me! Using a horizontal colour bar ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ An option to use a horizontal colour bar instead of the default vertical arrangement is given in the ``colour bar options`` option in the :ref:`sec:menu-r`. Using ‘plot-hugging’ colour bars ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:colourbarstyle`. Using floating/inset colour bars ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:colourbarstyle`. Plotting ticks on only one side of the colour bar ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:colourbarstyle`. Changing the text in the colour bar label ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:setprojlabel`. .. _sec:colournotrender: Using coloured particles instead of rendering to pixels ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ As a simpler alternative to interpolating to a pixel array, particles can simply be coloured according to the value of a particular quantity by setting the ``use particle colours not pixels`` option in the :ref:`sec:menu-r`. With this option set, :ref:`sec:renderplot` are simply plotted by colouring the particles according to the rendered field. This is somewhat cruder but can be a good indication of where individual particles might be affecting results. .. danger:: Any colouring of the particles set in :ref:`sec:interactive` will be overwritten by use of this option. Using normalised interpolations ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A normalised interpolation to pixels can be used by setting the ``normalise interpolations`` option from the :ref:`sec:menu-r`. In general this leads to smoother rendering but also means that edges and surfaces appear more prominently (and a bit strange). The rule-of-thumb I suggest is to use this option when there are no free surfaces in the simulation. .. warning:: Normalising a 3D column density rendering means plotting the quantity :math:`\int \rho {\rm d}z / \int {\rm d}z`, which is a bit meaningless. More useful is to turn on :ref:`sec:densityweighted`, which gives a mass-weighted line of sight average. For example, plotting temperature, this would give :math:`\int \rho T {\rm d}z / \int \rho {\rm d}z` which is more meaningful. Speeding up the rendering on 3D column integrated plots ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Interpolation on 3D column integrated plots can be made faster by setting the ``use accelerated rendering`` option in the :ref:`sec:menu-r`. The reason this is an option is that it makes a small approximation by assuming that each particle lies exactly in the centre of a pixel. In general this works very well but is not set by default because it can produce funny looking results when the particles are aligned on a regular grid (e.g. as is often the case in initial conditions). Typical speed-ups range from :math:`\times 2` up to :math:`\times 4`, so it is highly recommended for interactive work. .. _sec:densityweighted: Density weighted interpolation ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Density weighted interpolation (where a quantity is plotted times :math:`\rho`) can be turned on in the :ref:`sec:menu-r`. Selecting and rendering only a subset of the particles ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ An example of how to render using only a selected subset of the particles was given in :ref:`sec:rendersubset`. .. _sec:setprojlabel: Changing the label used for 3D projection plots ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The labelling scheme used to determine the colour bar label can be changed via the ``customize label on projection plots`` option in the :ref:`sec:menu-r`. Information specific to the quantity being rendered can be incorporated via format codes as follows: :: Example format strings: \(2268) %l d%z %uz : this is the default format "\int rho [g/cm^3] dz [cm]" column %l : would print "column density" for density surface %l : would print "surface density" %l integrated through %z : would print "density integrated through z" Format codes: %l : label for rendered quantity %z : label for 'z' %uz : units label for z (only if physical units applied) Changing “column density” to “surface density” on 3D plots ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:setprojlabel`. Changing the interpolation kernel ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The kernel used for the interpolations is by default the M\ :math:`_{4}` cubic B-spline, which has been standard in SPH calculations since the mid-1980’s. Other kernels can be selected via the ``change kernel`` option in the :ref:`sec:menu-r`. The kernel can also be changed by setting the ``SPLASH_KERNEL`` environment variable to either the kernel name as listed in the :ref:`sec:menu-r`, or something sensible resembling it. At present only a few kernels are implemented, with ``cubic`` , ``quartic`` and ``quintic`` referring to the M\ :math:`_{4}`, M\ :math:`_{5}` and M\ :math:`_{6}` B-splines with support of 2h and 3h, respectively. See [Price12]_ for more details. .. _sec:menu-v: (v)ector plot options --------------------- .. image:: figs/menu-v.png :width: 50.0% Changing the number of arrows on vector plots ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ See :ref:`sec:vecpix`. .. _sec:vecpix: Changing the number of pixels in vector plots ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The number of pixels used on :ref:`sec:vectorplots` can be changed via the ``change number of pixels`` option in the :ref:`sec:menu-v`. This controls the number and average size of the arrows which appear (i.e., one arrow is plotted at the centre of each pixel). Changing the size of arrows on vector plots ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The size of the arrows on :ref:`sec:vectorplots` is proportional to the magnitude of the vector quantity at that pixel, where the maximum size is set from the maximum plot limit for the x, y and z components of the vector quantity being plotted such that the longest arrow fills one pixel. These limits can be changed manually via the :ref:`sec:menu-l` options. Where these limits are nowhere near the actual values of the vector field, arrows can appear either very big (just a line across the screen) or extremely small (appearing as just dots). Pressing ``w`` in :ref:`sec:interactive` automatically adjusts the arrows to sensible proportions (this is the equivalent of pressing ``a`` for non-vector quantities). Alternatively pressing ``v`` (to decrease) or ``V`` (to increase) can be used to adjust the arrow lengths (the change can be multiplied by 10 or more by first pressing ``z`` one or more times before pressing ``v`` or ``V``). Plotting vector arrows in white instead of black or vice-versa ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Vector arrows are by default plotted using the current foreground colour index (i.e., as used for plotting the axes). To plot in the background colour index instead set the ``use background colour for arrows`` option in the :ref:`sec:menu-v`. Turning off the legend for vector plots ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The legend which appears on :ref:`sec:vectorplots` can be turned on or off via the ``vector plot legend settings`` option in the :ref:`sec:menu-v`. Moving the vector plot legend ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The position of the :ref:`sec:vectorplots` legend can be set either interactively by positioning the mouse and pressing ``H`` or manually via the ``vector plot legend settings`` option in the :ref:`sec:menu-v`. Plotting stream/fieldlines instead of arrows ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ To plot :ref:`sec:vectorplots` that use stream/fieldlines instead of arrows, set the ``plot stream/field lines instead of arrows`` option in the :ref:`sec:menu-v`. This option performs a simple integration of the interpolated vector field to get the stream function, the contours of which are then plotted .. hint:: The number of contours can be changed via the ``change number of contours`` option in the :ref:`sec:menu-r`. It is generally advantageous to use a larger number of pixels for the vector interpolation (See :ref:`sec:vecpix`) to get smooth contours. At present this option works quite well for smooth vector fields but can perform poorly for vector fields with strong gradients. Turning arrow heads off for vector plots ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ :ref:`sec:vectorplots` can be plotted using arrows without heads using the ``turn arrow heads on/off`` option in the :ref:`sec:menu-v`. Hiding vector arrows where there are no SPH particles ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ On :ref:`sec:renderplot` often arrows can appear where there are apparently no SPH particles because the interpolation is performed to all pixels within :math:`2h` of an SPH particle. Such arrows in regions of few or no particles can be hidden using the ``hide arrows where there are no particles`` option in the :ref:`sec:menu-v`. A threshold number of particles for each pixel can be specified, below which no arrow will be plotted on that pixel. Plotting a vector plot in a cross section slice ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ :ref:`sec:vectorplots` are either in a :ref:`sec:xsec` or are column integrated projections depending on the setting of the ``switch between cross section/projection`` option in the :ref:`sec:menu-x`. Setting this to cross section and plotting :ref:`sec:vectorplots` produces a vector plot in a cross section slice. Making all arrow the same length (i.e., showing direction only, not magnitude) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ An option to plot all vector arrows of the same length (instead of the default option where the length of the arrow is proportional to the vector magnitude) can be set from the :ref:`sec:menu-v`. .. _sec:menu-x: (x) cross section/3D plotting options ------------------------------------- .. image:: figs/menu-x.png :width: 50.0% Plotting a cross section slice through 3D data ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ When plotting :ref:`sec:renderplot` of 3D data, the default option is to plot a column-integrated plot. To change this to a :ref:`sec:xsec`, use option 1) in the :ref:`sec:menu-x` (``switch between cross section/projection``). See :ref:`sec:basic` for examples of how this works. An oblique :ref:`sec:xsec` can be set interactively using the ``x`` key, see :ref:`sec:obliquexsec` which works by setting a combination of rotation and a :ref:`sec:xsec` position. Plotting a cross section line through 2D data ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In 2D, setting the ``switch between cross section/projection`` option in the :ref:`sec:menu-x` to :ref:`sec:xsec` means that :ref:`sec:renderplot` are in fact a 1D :ref:`sec:xsec` (i.e., a line) through 2D data. The position of the line is completely arbitrary (i.e., can be set for oblique cross sections as well as straight lines) and is set interactively after the usual :math:`y-` and :math:`x-` axis prompts. Rotating the particles ~~~~~~~~~~~~~~~~~~~~~~~ An angle of rotation about may be set each axis may be set in the :ref:`sec:menu-x` using the ``rotation on/off/settings`` option or interactively (press ``h`` in :ref:`sec:interactive` to see the exact keystrokes). The position of the origin about which particles are rotated can be set from the ``rotation on/off/settings`` option in the :ref:`sec:menu-x`. Rotated axes or boxes can be plotted using the ``set axes for rotated/3D plots`` option in the same menu. Rotations are performed in the order :math:`z-y-x`. This means that the :math:`y-` rotation angle is an angle about the *new* :math:`y-`\ axis, defined by the :math:`z` rotation and similarly for the :math:`x-` rotation. If you think about it long enough, it makes sense. If in doubt, do it interactively and set the angles in the order :math:`z-y-x`. Setting the origin about which particles are rotated ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The origin about which particles are rotated and relative to which the radius is calculated when the ``calculate extra quantities`` option is set in the :ref:`sec:menu-d` can be changed via the ``rotation on/off/settings`` option in the :ref:`sec:menu-x`. .. _sec:3Dperspective: Adding 3D perspective ~~~~~~~~~~~~~~~~~~~~~~ 3D perspective can be turned on via the ``3D perspective on/off`` option in the :ref:`sec:menu-x`. Prompts for setting the perspective position then appear after the usual prompts for y and x axes, :ref:`sec:renderplot` and :ref:`sec:vectorplots`, i.e., something like the following: :: Please enter your selection now (y axis or option):2 (x axis) (default=1): (render) (0=none) ([0:20], default=0): (vector plot) (0=none, 7=B, 10=v, 17=J) ([0:17], default=0): enter z coordinate of observer (default=1.800): enter distance between observer and projection screen ([0.000:], default=0.1800): Graphics device/type (? to see list, default /xwin): 3D perspective is defined by two parameters: a distance to the observer :math:`zobs` and a distance between the observer and a screen placed in front of the observer, :math:`dscreen`. The transformation from usual :math:`x` and :math:`y` to screen :math:`x'` and :math:`y'` is then given by .. math:: \begin{aligned} x' & = & x*dscreen/(zobs-z), \nonumber \\ y' & = & y*dscreen/(zobs-z).\end{aligned} This means that objects at the screen distance will have unit magnification, objects closer than the screen will appear larger (points diverge) and objects further away will appear smaller (points converge). The situation could be beautifully illustrated if I could be bothered drawing a figure. I have found reasonable results with something like a :math:`1/10` reduction at the typical distance of the object (i.e., observer is placed at a distance of :math:`10\times` object size with distance to screen of :math:`1\times` object size). splash sets this as default using the z plot limit as the ‘object size’. .. hint:: The position of the 3D observer in :math:`z` can also be changed in :ref:`sec:interactive` using ``u`` or ``U`` (to move ’up’) and ``d`` or ``D`` (to move ``down``). .. _sec:surface: Using 3D surface rendering ~~~~~~~~~~~~~~~~~~~~~~~~~~~ 3D surface rendering (turned on using the ``3D surface rendering on/off`` option in the :ref:`sec:menu-x`) performs a ray-trace through the particle data, thus visualising the "last scattering surface". When set, the user is prompted for an "optical depth" before plotting which determines the position of the surface. Only applies to 3D data. When set with cross-section (instead of projection), particles at or below the z value of the slice are used. For examples of the 3D surface rendering in splash , have a look at my movies of neutron star mergers: http://users.monash.edu.au/~dprice/research/nsmag. Plotting 3D box / 3D axes ~~~~~~~~~~~~~~~~~~~~~~~~~~ Rotated axes or boxes can be plotted using the ``set axes for rotated/3D plots`` option in the :ref:`sec:menu-x`. .. _sec:animseq: Setting up animation sequences ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Animation sequences can be set via the ``set animation sequence`` option in the :ref:`sec:menu-x`. At present the possible sequences that can be added are: :: 1 : steady zoom on x and y axes 2 : steady rotation 3 : steady change of limits (e.g. for colour bar) 4 : steady movement of 3D observer 5 : sequence of cross section slices through a 3D box 6 : steady change of opacity for 3D surface plots Up to one sequence of each type can be added (i.e., up to 6 in total) with different start and end points (specified in terms of dump file number), with the additional possibility of inserting extra frames between dump files (e.g. to plot a sequence of frames consisting of a changing view of the same dump file). Animation sequences can also be set using ``e`` in :ref:`sec:interactive`. To set a sequence interactively first adjust the plot settings to correspond to the start of the sequence (pressing ``s`` to save if this is done in :ref:`sec:interactive`). Then in :ref:`sec:interactive` move to the dump file you want to be the end-point and also adjust the plot settings to correspond to the end-point of your desired sequence (i.e., adjust the colour bar limits and/or adjust the rotation angle and/or the x/y limits and/or the 3D observer position and/or the opacity). Then, rather than pressing ``s`` (which would make these become the default plot settings) press ``e`` instead, saving these settings as the end-point of the desired animation sequence. This can be done multiple times to set multiple sequences. Animation sequences set up in this manner are saved to a file called ``splash.anim`` either when prompted (if setting sequences non-interactively) or by pressing ’S’ from the main menu which then saves both the ``splash.limits`` and ``splash.anim`` files in addition to the usual ``splash.defaults`` file. **Note:** Animation sequences act on a ‘per page’ basis rather than simply ‘per frame’. This means that you can produce a multi-panelled movie (e.g.) showing the evolution of different runs side by side, with the same animation sequence applied to each. Plotting a sequence of frames rotating a data set through 360 degrees ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This can be achieved by setting an animation sequence with a steady change of rotation angle. See :ref:`sec:animseq`. Plotting a ‘fly-around’ of 3D data ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This can be achieved by setting an animation sequence with a steady change of rotation angle. See :ref:`sec:animseq`. Plotting a flythru of 3D data ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A sequence of :ref:`sec:xsec` slices progressively deeper into a 3D box or alternatively a steady movement of the 3D observer (on projection plots) can be plotted by setting up an animation sequence. See :ref:`sec:animseq`. Adding a steady zoom sequence to a movie ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A steady change of :math:`x-` and :math:`y-` limits can be added by setting up an animation sequence. See :ref:`sec:animseq`. Adding a steady change of colour bar limits ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A steady change of limits on the colour bar over one or more dump files for a movie can be implemented by setting up an animation sequence. See :ref:`sec:animseq` for details. .. _sec:move3Dobserver: Adding steady movement of the 3D observer ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The position of the 3D observer can be steadily changed over several dump files (or several frames produced of the same dump file) by setting up an animation sequence. See :ref:`sec:animseq` for details. Miscellaneous other useful things --------------------------------- .. _sec:menu-h: My attempt at in-built help ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. image:: figs/menu-h.png :width: 50.0% The :ref:`sec:menu-h` does nothing particularly useful apart from tell you about menu shortcuts (see :ref:`sec:menushortcuts`). It seemed like a good idea at the time… .. _sec:menushortcuts: Keyboard shortcuts to menu options ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. image:: figs/menu-x1.png :width: 50.0% Menu options which normally require two keystrokes (e.g. x menu, option 1) can be shortcut to by simply typing the letter and number together at the main menu prompt (so e.g. ``x1`` for x menu, option 1, ``r2`` for render menu, option 2, etc.). Exiting splash ~~~~~~~~~~~~~~~~ .. image:: figs/menu-q.png :width: 50.0% (q)uit, unsurprisingly, quits. Typing a number greater than the number of data columns also exits the program (e.g. I often simply type 99 to exit).