.. _plotexample-acoustics-1d-5: 
 
Automatically compute ylimits from data
=======================================

This example illustrates how to determine the ylimits that should be set on
each axis based on the data.  

One could use::
 
  plotaxes.ylimits = 'auto'

for each variable to have them automatically set by matplotlib, but then
they would be reset for each frame as the solution evolves.

Instead, this example uses a function `pyclaw.plotters.frametools.var_limits`
that reads in all the data files and determines limits for a set of
specified variables.
 
 

Example generating data: `$CLAW/doc/sphinx/example-acoustics-1d/README.html <../example-acoustics-1d/README.html>`_

Resulting plots: `$CLAW/doc/sphinx/example-acoustics-1d/plots_5/_PlotIndex.html <../example-acoustics-1d/plots_5/_PlotIndex.html>`_

::

    
    #--------------------------
    def setplot(plotdata):
    #--------------------------
        
        """ 
        Specify what is to be plotted at each frame.
        Input:  plotdata, an instance of pyclaw.plotters.data.ClawPlotData.
        Output: a modified version of plotdata.
        
        """ 
        from pyclaw.plotters.frametools import var_limits
    
    
        plotdata.clearfigures()  # clear any old figures,axes,items data
    
        vars = [0,1]   # variables to be plotted
        use_global_limits = True
        if use_global_limits:
            # scan all frames and to determine limits
            # padding parameter adds a bit to varmin and varmax for plot limits.
            varmin,varmax,varlim = var_limits(plotdata,vars,padding=0.1)
    	plimits = varlim[0]
    	ulimits = varlim[1]
        else:
    	plimits = 'auto'   # or set to known limits
    	ulimits = 'auto'
    
    
        # Figure for q[0]
        plotfigure = plotdata.new_plotfigure(name='Solution', figno=1)
    
        # Set up for axes in this figure:
        plotaxes = plotfigure.new_plotaxes()
        plotaxes.xlimits = 'auto'
        plotaxes.ylimits = plimits
        plotaxes.title = 'Pressure'
    
        # Set up item on these axes:
        plotitem = plotaxes.new_plotitem(plot_type='1d')
        plotitem.plot_var = 0
        plotitem.plotstyle = 'o-'
        plotitem.color = 'b'
    
        
        # Figure for q[1]
        plotfigure = plotdata.new_plotfigure(name='Velocity', figno=2)
    
        # Set axes in this figure:
        plotaxes = plotfigure.new_plotaxes()
        plotaxes.xlimits = 'auto'
        plotaxes.ylimits = ulimits
        plotaxes.title = 'Velocity'
    
        # Set up for item on these axes:
        plotitem = plotaxes.new_plotitem(plot_type='1d')
        plotitem.plot_var = 1
        plotitem.plotstyle = 'o-'
        plotitem.color = 'r'
    
        # Parameters used only when creating html and/or latex hardcopy
        # e.g., via pyclaw.plotters.frametools.printframes:
    
        plotdata.printfigs = True                # print figures
        plotdata.print_format = 'png'            # file format
        plotdata.print_framenos = 'all'          # list of frames to print
        plotdata.print_fignos = 'all'            # list of figures to print
        plotdata.html = True                     # create html files of plots?
        plotdata.html_homelink = '../README.html'# pointer for index page
        plotdata.latex = True                    # create latex file of plots?
        plotdata.latex_figsperline = 2           # layout of plots
        plotdata.latex_framesperline = 1         # layout of plots
        plotdata.latex_makepdf = True            # also run pdflatex?
    
        return plotdata