SESSION 17		ADVANCED GNUPLOT

1. This session demonstrates just about the whole range of gnuplot's 
capabilities. The demonstration takes the form of three tutorials 
corresponding to 2D, 3D and 3D contour plots. 

The three subdirectories `gnu_2d', `gnu_3d' and `gnu_contour', within the 
directory `gnu_adv', contain notes and an example program for 2-D, 3-D and 3-D
contour plots respectively.

Position yourself in the directory `gnu_adv'. 

Now change to the required subdirectory and read the relevant notes and 
instructions, e.g.

		cd gnu_2d
		more notes_2d


2. Exercises

a) Plot a graph of the function `x*x/(x-5) + x*x*x/(x+10) + x/(x-20)' with an 
   xrange [-40:40] and yrange [-1000:1500].
   By setting `samples' to a suitable value, plot a smoothened version of this
   function. Access gnuplot's on-line help facility if you are unsure how to
   do this.

b) Plot the function `z = -sqrt(x*sin(0.5*x) + 0.5*y*sin(y))' with a range of
   [-3:3] for x, [-2:3] for y, and [-1.5:0] for z. 
   Plot again with the `hidden3d' option in force. 
   Plot again by setting `isosamples' to 50,50. Try using the help facility 
   if you aren't sure how to do this.

c) Plot the contents of the datafile `fort.21' in the `gnu_3d' subdirectory
   of `gnu_adv' by specifying the 3rd column as x, the 1st column as y and
   the 2nd as z, and using the line style.  
   What extra command is required when plotting a 3D datafile compared to a 
   3D function?


END OF SESSION 17					file advanced17
