# HG changeset patch
# User Jaroslav Hajek <highegg@gmail.com>
# Date 1266391146 -3600
# Node ID ade59ae10e80f1999ce51f3e3261c9daeb33bab1
# Parent  8b3cfc1288e2320137d4840b5fa227e3fdceb51f
slight optimization in interp2

diff --git a/scripts/ChangeLog b/scripts/ChangeLog
--- a/scripts/ChangeLog
+++ b/scripts/ChangeLog
@@ -1,3 +1,7 @@
+2010-02-17  Jaroslav Hajek  <highegg@gmail.com>
+
+	* general/interp2: Slightly optimize linear interpolation.
+
 2010-02-12  Jaroslav Hajek  <highegg@gmail.com>
 
 	* general/interp2: Remove debug stub.
diff --git a/scripts/general/interp2.m b/scripts/general/interp2.m
--- a/scripts/general/interp2.m
+++ b/scripts/general/interp2.m
@@ -221,8 +221,8 @@
       idx = sub2ind (size (a), yidx, xidx);
 
       ## scale XI, YI values to a 1-spaced grid
-      Xsc = (XI - X(xidx)) ./ (X(xidx + 1) - X(xidx));
-      Ysc = (YI - Y(yidx)) ./ (Y(yidx + 1) - Y(yidx));
+      Xsc = (XI - X(xidx)) ./ (diff (X)(xidx));
+      Ysc = (YI - Y(yidx)) ./ (diff (Y)(yidx));
 
       ## apply plane equation
       ZI = a(idx) + b(idx).*Xsc + c(idx).*Ysc + d(idx).*Xsc.*Ysc;