diff -ru ./octave-forge-2006.03.17.orig/main/geometry/griddata.m ./octave-forge-2006.03.17/main/geometry/griddata.m
--- ./octave-forge-2006.03.17.orig/main/geometry/griddata.m	2004-09-01 12:04:42.000000000 -0700
+++ ./octave-forge-2006.03.17/main/geometry/griddata.m	2004-09-01 12:06:10.228458056 -0700
@@ -49,7 +49,7 @@
   [nr,nc]=size(xi);
   
   ## triangulate data
-  tri=delaunay(x,y);
+  tri=delaunay(x,y,"QJ");
   zi=zeros(size(xi));
   
   if strcmp(method,'cubic')