Add Midpoint2DIntegral as standalone function

git-svn-id: http://svn.einsteintoolkit.org/cactus/EinsteinAnalysis/Multipole/trunk@92 4f5cb9a8-4dd8-4c2d-9bbd-173fa4467843

2 files changed, 17 insertions, 0 deletions

diff --git a/src/integrate.cc b/src/integrate.cc
index 1a9f44b..90a27d9 100644
--- a/src/integrate.cc
+++ b/src/integrate.cc
@@ -34,6 +34,20 @@ the integral.
 
 // Hard coded 2D integrals
 
+CCTK_REAL Midpoint2DIntegral(CCTK_REAL const *f, int nx, int ny, CCTK_REAL hx, CCTK_REAL hy)
+{
+  CCTK_REAL integrand_sum = 0.0;
+  int ix = 0, iy = 0;
+
+  assert(nx > 0); assert(ny > 0); assert (f);
+
+  for (iy = 0; iy <= ny; iy++)
+    for (ix = 0; ix <= nx; ix++)
+      integrand_sum += f[idx(ix,iy)];
+
+  return hx * hy * integrand_sum;
+}
+
 static CCTK_REAL Trapezoidal2DIntegral(CCTK_REAL const *f, int nx, int ny, CCTK_REAL hx, CCTK_REAL hy)
 {
   CCTK_REAL integrand_sum = 0.0;
diff --git a/src/integrate.hh b/src/integrate.hh
index 5bcd43f..168fd2f 100644
--- a/src/integrate.hh
+++ b/src/integrate.hh
@@ -3,6 +3,9 @@
 #define __integrate_h
 #include "cctk.h"
 
+CCTK_REAL Midpoint2DIntegral(CCTK_REAL const *f, int nx, int ny,
+                             CCTK_REAL hx, CCTK_REAL hy);
+
 CCTK_REAL Simpson2DIntegral(CCTK_REAL const *f, int nx, int ny, 
                             CCTK_REAL hx, CCTK_REAL hy);