You can also use jfig for simple function plotting via the jfig.utils.MHG class. Unlike the low-level API of most jfig classes (which are based on the internal coordinate systems with a fixed resolution of 2400 dpi), MHG allows you to specify your own custom coordinate transformation and a calling interface similar to the industry-standard Matlab Handle-Graphics functions (hence, MHG). For details and documentation about Matlab and its graphics see the www.mathworks.com website.

The following image shows a typical plot created via MHG, including axes, axes labels, grid, a line-plot, and markers:

Please check the gallery page for a few additional plotting examples. For each example, the Jython script (see below) used to create that figure is included, too.

Naturally, the plot functions in jfig are not meant as a fully-featured replacement of tools like Matlab, Mathematica, or gnuplot. Still, the provided functions should be useful for a variety of simple plotting needs, and you can use all jfig editing commands to edit, label, and modify your figures. Also, you can easily add your own functions with a little bit of Jython or Java programming.

Supported functions

  figure()           - create new figure window with default size
  figure( figure )   - make given figure the current figure
  gcf()              - return reference to current figure (or null)
  clf()              - clear current figure window
  close()            - close current figure window
  close( figure )    - close specified window
  closeAllFigures()  - close all figure windows
  getFigures()       - array with references to all figures

  reshape( xxyy[] )  - set window size to specified fraction of screen
  fullscreen()       - create new 'fullscreen' window
  hide( figure )     - hide the figure window, but don't close it
  show( figure )     - show the figure window
  doZoomFit()        - zoom fit of window contents to current size

  save( file )       - save current figure to specified file

  gca()              - return current axes (=coordinate transformation)
  cla()              - clear axes, reset transformation
  axis( xxyy[] )     - set world-coordinates transformation
  axis( string )     - set world-coordinates transformation
  title()            - set figure title
  xlabel()           - set label of x-axis
  ylabel()           - set label of y-axis
  plotGrid()         - plot a grid (grid lines at axis markers)
  plotCartesianAxes()- axes (markers at default or specified positions)

  line()             - plot a line (several variants)
  patch()            - plot a polygon (several variants)
  fill()             - plot and fill a polygon (several variants)
  plot()             - line or marker plot (several variants)
  stem()             - stem plot (several variants)
  bar()              - bar-graph plot (several variants)
  stairs()           - stair-step plot
  image()            - image-plot (matrix display)
  marker()           - plot a single marker
  text()             - plot a single text object

  color( string )    - parse a color from a string, e.g. 0xff0056
  color( r,g,b )     - return a rgb color 0..r,g,b..1
  colormap( name )   - set selected colormap, e.g. 'jet', 'autumn'
  getColormap()      - return reference to current colormap
  colorbar()         - plot colorbar

Scripting with Jython

  rem  this is for Windows, use similar code for Unix/Linux/Mac
  set CLASSPATH=c:\temp\jython.jar;c:\temp\jfig3.jar; ...
  cd c:\temp
  jython

  Jython 2.2a0 on java1.4.2 (JIT: null)
  Type "copyright", "credits" or "license" for more information.
  >>>

  from math import pi
  from jfig.utils import Array       # several array utilities
  from jfig.utils import MHG         # the plot functions
  m = MHG()                          # initalize the plot library,
                                     # reference via variable m
  N = 200
  x = Array.linspace(0,10,N)         # 200 values (0.0 .. 10.0)
  y = Array.cos(x)                   # vector with cos(x)
  z = Array.random(N)                # 200 random values, range [0,1]
  z = Array.add( z, -0.3 )           # shift to range [-0.3, 0.7]

  m.figure();                        # new plot window
  m.gca().autoscaleTight( x, y )     # default scaling
  m.plot( x, y, '-b' )               # solid-blue-line plot
  m.plot( x, z, '.r' )               # red-dot markers
  m.xlabel( 'x' )                    # x-axis label
  m.ylabel( 'sin(x), random data' )  # y-axis label
  m.plotCartesianAxes()              # axes
  m.plotGrid()                       # grid
  m.doZoomFit()
  
  from java.io import File
  m.save( File( 'plot1.fig' ))       # save figure