Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
Hello, all; I don't know whether anybody had raised any doubts or questions on the reliability of the results by triangulate and trigrid. I had some irregular-gridded data from satellite ( about 1000 points for northern hemisphere) and wanted to fit them to a regular grid. I knew there were three big value points near each other and intuitively I would think they must come from a big-value area around this three points. Actually I binned the data into lat/lon boxes and took weighted averages and I got this big-value area. But when I used the procedures triangulate and trigrid, the result came like two big-value areas each of which centered on one of those three points with the low-value node between them. You know that was incorrect for the sense of interpolation. Later I found that this was due to the selection of the Delaunay triangulation. The triangulate procedure would select the points that far away those three points as triangulates and made the interpolation by them. It seems if there were a second trianulation algorithms, they would gave a much different result. Have you guys met this kind of problem before ? Your suggestion would be very appreciated. Regards, Chunhua