Index: /branches/eam_branches/20091201/ppSim/src/ppSimMakeStarGrid.c
===================================================================
--- /branches/eam_branches/20091201/ppSim/src/ppSimMakeStarGrid.c	(revision 26375)
+++ /branches/eam_branches/20091201/ppSim/src/ppSimMakeStarGrid.c	(revision 26375)
@@ -0,0 +1,70 @@
+# include "ppSim.h"
+
+# define ESCAPE(MSG) { \
+  psError(PS_ERR_BAD_PARAMETER_VALUE, true, MSG); \
+  return false; }
+
+bool ppSimMakeStarGrid(psArray *stars, pmFPA *fpa, pmConfig *config, const psRandom *rng) {
+
+    bool status;
+    assert (stars);
+
+    psMetadata *recipe = psMetadataLookupMetadata(&status, config->recipes, PPSIM_RECIPE); // Recipe
+
+    bool starsGrid = psMetadataLookupBool(&status, recipe, "STARS.GRID"); // Grid of stars
+    if (!starsGrid) return true;
+
+    float starMag = psMetadataLookupF32(&status, recipe, "STARS.GRID.MAG"); // magnitude of grid stars
+    float dX  	  = psMetadataLookupS32(&status, recipe, "STARS.GRID.DX"); // grid spacing in X
+    float dY  	  = psMetadataLookupS32(&status, recipe, "STARS.GRID.DY"); // grid spacing in Y
+
+    float expTime      = psMetadataLookupF32(&status, recipe, "EXPTIME"); // Exposure time
+    float zp           = psMetadataLookupF32(&status, recipe, "ZEROPOINT"); // Photometric zero point
+    float seeing       = psMetadataLookupF32(&status, recipe, "SEEING"); // Seeing SIGMA (pixels)
+    float scale        = psMetadataLookupF32(&status, recipe, "PIXEL.SCALE") * M_PI / 3600.0 / 180.0; // Plate scale (radians/pixel)
+
+    if (isnan(expTime))  ESCAPE("EXPTIME is not defined");
+    if (isnan(zp))       ESCAPE("ZEROPOINT is not defined");
+    if (isnan(seeing))   ESCAPE("SEEING is not defined");
+    if (isnan(scale))    ESCAPE("PIXEL.SCALE is not defined");
+
+    // Size of FPA
+    psRegion *bounds = ppSimFPABounds (fpa);
+
+    // Size of focal plane (can't I get this from the config?)
+    int xSize = bounds->x1 - bounds->x0;
+    int ySize = bounds->y1 - bounds->y0;
+    psFree(bounds);
+
+    int nX = xSize / dX;
+    int oX = 0.5*dX;
+
+    int nY = ySize / dY;
+    int oY = 0.5*dY;
+
+    psLogMsg("ppSim", PS_LOG_INFO, "Adding %d stars with %f mag\n", nX * nY, starMag);
+
+    long oldSize = stars->n;
+    psArrayRealloc (stars, stars->n + (nX * nY));
+
+    int i = 0;
+    for (int ix = 0; ix < nX; ix ++) {
+	for (int iy = 0; iy < nY; iy ++) {
+
+	    ppSimStar *star = ppSimStarAlloc ();
+
+	    // make fpa center of distribution
+	    star->x    = oX + dX*ix; // x position
+	    star->y    = oY + dY*iy; // y position
+
+	    star->flux = ppSimMagToFlux (starMag, zp) * expTime;
+	    star->peak = ppSimStarFluxToPeak (star->flux, seeing);
+
+	    stars->data[oldSize + i] = star;
+	    i++;
+	}
+    }
+    stars->n = oldSize + i;
+
+    return true;
+}