[killtimm]

I have a 2D unstructured mesh datafile which has the following format (for each cell, x1, x2 and x3 are different, so are with y values ):

x1 y1 Mach1
x2 y2 Mach2
#blank____________________________(for cell 1)
x3 y3 Mach3
x3 y3 Mach3
#blank
#blank
x1 y1 Mach1
x2 y2 Mach2
#blank____________________________(for cell 2)
x3 y3 Mach3
x3 y3 Mach3
#blank
#blank

...... ...... #for cell N


It's ok that a colored contour map could be made with pm3d
But I want to plot a contour with just black isolines like below:

Somebody may say that it can be realized using dgrid3d
But it will be impossible if the mesh is very large to consume
too much memory

Can anyone tell me how to plot the contour isolines like above?

It won't be better if commands are presented

Thanks in advance!

[DoHander]

You can check Tecplot (if you have an academic license) - they have a lot of examples of how to plot these kind of data.

About Gnuplot - this is a good choice if you are a programmer, check the last version of Gnuplot, especially the demos directory - I'm sure you will found an example of isolines.

http://www.gnuplot.info/
http://sourceforge.net/projects/gnuplot/files/

Do

[DoHander]

Here - some Gnuplot demos:

http://gnuplot.sourceforge.net/demo_4.2/
http://gnuplot.sourceforge.net/demo_4.2/contours.html

The last version is 4.4 probably you will find more demos.