Here is a short summary of Octave's new plotting features.

There are two basic plotting commands, gplot and gsplot, that have a
syntax very much like gnuplot's plot and splot commands.  There are
also a number of other plot commands that have a syntax much like
Matlab's plotting commands.  All of the Matlab-style plotting commands
are implemented in M-files using the gplot and gsplot commands.

  gplot  <ranges> expression <using> <title> <style>

  gsplot <ranges> expression <using> <title> <style>

where items in angle brackes are optional, and the <using>, <title>
and <style> qualifiers may appear in any order.  You may plot multiple
expressions with a single command by separating them with colons.
Each expression may have its own set of qualifiers.

The expression must not contain any literal matrices (e.g. [1,2;3,4])
since it is nearly impossible to distinguish a plot range from a
matrix of data.

See the help for gnuplot for a description of the syntax for the
optional items.

By default, the gplot command plots the second column of a matrix
versus the first.  If the matrix only has one column, it is taken as a
vector of y coordinates and the x coordinate is taken as the element
index, starting with zero.  If there are more than two columns, you
can choose which columns to plot with the <using> qualifier.
  
Examples:

  gplot rand (100,1) with linespoints

  x = (-10:0.1:10)';
  data = [x, sin(x), cos(x)];
  gplot [-10:10] [-1.1:1.1] data with lines, data using 1:3 with impulses

In addition, the whole range of gnuplot set and show commands are
available, as is replot.

Examples:

  set term tek40
  set title "sine with lines and cosine with impulses"
  replot
  show title


The additional Matlab-style plotting commands are:

  plot            -- 2D plots
  semilogx        -- 2D semilog plot with logscale on the x axis
  semilogy        -- 2D semilog plot with logscale on the y axis
  loglog          -- 2D log-log plot
  mesh            -- 3D mesh plot
  meshdom         -- create matrices for 3D plotting from two vectors
  contour         -- contour plots of 3D data
  bar             -- create bar graphs
  stairs          -- create stairstep plots
  polar           -- 2D plots from theta-R data
  grid            -- turn plot grid lines on or off
  xlabel, ylabel  -- place labels on the x and y axes of 2D plots

Help for all of these commands is available at the Octave prompt.

Finally, there are three additional commands

  sombrero        -- An exmample of 3D plotting.

  closeplot       -- Close stream to the gnuplot subprocess.  If you
                     are using X11, this will close the plot window.

  purge_tmp_files -- Delete temporary files created by plotting commands.
                     Octave creates temporary data files for gnuplot
                     and then sends commands to gnuplot through a
                     pipe.  Octave will delete the temporary files on
                     exit, but if you are doing a lot of plotting you
                     may want to clean up in the middle of a session.

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