Vector format export of trisurf plot shows triangulation edges

I've made a contour plot of scattered data z = f(x,y) using the following code:

load data.mat % contains scattered x,y,z

tri = delaunay([x,y]);

trisurf(tri,x,y,z);

shading interp

set(gca,'view',[0 90])

This looks fine on screen but the edges of the triangulation show up in light gray when the image is exported in *.eps or *.pdf format. I've tried setting the 'EdgeColor' to 'none' and 'interp', but this has no effect.

The edges don't show up in the pixelated graphics formats, but then obviously I lose the scalability of the figure.

No edges appear when interpolating the data to a regular grid and using contourf but this leaves a stepped boundary around the edge of the scattered data.

Is there an export option to avoid this, or a better way to make a contour plot of scattered data. E.g. why can't the triangulation be 2D and just the colouring represent the height z?

[Jean-Philippe]

I have the exact same problem, I have almost the same script as William and it does the same thing. Does anyone know about this?