[cout,hout] = trisurfc(xin,yin,zin,N)

Regularly just called by with the following syntax to produce a plot:
trisurfc(xin,yin,zin,N)
Where xin,yin,zin are 1-D arrays of the x,y,z triples of the points in your mesh.

Contouring and surface function for functions defined on triangular meshes
xin, yin, zin, are arrays of x,y,z values of the points for your surface.
So [x(1) y(1) z(1)] defines the first point, etc.
The last input N defines the contouring levels. There are several options:
N scalar - N number of equally spaced contours will be drawn
N vector - Draws contours at the levels specified in N

A special call with a two element N where both elements are equal draws a single contour at that level.

[C,H] = TRISURFC(...)
This syntax can be used to pass the contour matrix C and the contour handels H to clabel by adding clabel(c,h) or clabel(c) after the call to TRICSURFC.

Contour line code by Darren Engwirda - 2005
Updated 15/05/2006
Surface code added by Jack Kohoutek - 2009