Index: trunk/psphot/src/models/pmModel_RGAUSS.c
===================================================================
--- trunk/psphot/src/models/pmModel_RGAUSS.c	(revision 4954)
+++ trunk/psphot/src/models/pmModel_RGAUSS.c	(revision 8882)
@@ -20,25 +20,25 @@
     psF32 *PAR = params->data.F32;
 
-    psF32 X  = x->data.F32[0] - PAR[2];
-    psF32 Y  = x->data.F32[1] - PAR[3];
-    psF32 px = PAR[4]*X;
-    psF32 py = PAR[5]*Y;
-    psF32 z  = 0.5*PS_SQR(px) + 0.5*PS_SQR(py) + PAR[6]*X*Y;
+    psF32 X  = x->data.F32[0] - PAR[PM_PAR_XPOS];
+    psF32 Y  = x->data.F32[1] - PAR[PM_PAR_YPOS];
+    psF32 px = PAR[PM_PAR_SXX]*X;
+    psF32 py = PAR[PM_PAR_SYY]*Y;
+    psF32 z  = 0.5*PS_SQR(px) + 0.5*PS_SQR(py) + PAR[PM_PAR_SXY]*X*Y;
 
     // psF32 FACT = 1 + 5*exp(-5*PAR[7]);
     
-    psF32 p  = pow(z, PAR[7] - 1.0);
+    psF32 p  = pow(z, PAR[PM_PAR_7] - 1.0);
     psF32 r  = 1.0 / (1 + z + z*p);
-    psF32 f  = PAR[1]*r + PAR[0];
+    psF32 f  = PAR[PM_PAR_FLUX]*r + PAR[PM_PAR_SKY];
 
     if (deriv != NULL) {
         // note difference from a pure gaussian: q = params->data.F32[1]*r
-        psF32 t = PAR[1]*r*r;
-	psF32 q = t*(1 + PAR[7]*p);
+        psF32 t = PAR[PM_PAR_FLUX]*r*r;
+	psF32 q = t*(1 + PAR[PM_PAR_7]*p);
 
         deriv->data.F32[0] = +1.0;
         deriv->data.F32[1] = +r;
-        deriv->data.F32[2] = q*(2.0*px*PAR[4] + PAR[6]*Y);
-        deriv->data.F32[3] = q*(2.0*py*PAR[5] + PAR[6]*X);
+        deriv->data.F32[2] = q*(2.0*px*PAR[PM_PAR_SXX] + PAR[PM_PAR_SXY]*Y);
+        deriv->data.F32[3] = q*(2.0*py*PAR[PM_PAR_SYY] + PAR[PM_PAR_SXY]*X);
         deriv->data.F32[4] = -q*px*X*2;
         deriv->data.F32[5] = -q*py*Y*2;
@@ -60,7 +60,7 @@
     psF32 *PAR = params->data.F32;
 
-    psF64 A1   = PS_SQR(PAR[4]);
-    psF64 A2   = PS_SQR(PAR[5]);
-    psF64 A3   = PS_SQR(PAR[6]);
+    psF64 A1   = PS_SQR(PAR[PM_PAR_SXX]);
+    psF64 A2   = PS_SQR(PAR[PM_PAR_SYY]);
+    psF64 A3   = PS_SQR(PAR[PM_PAR_SXY]);
     psF64 Area = 2.0 * M_PI / sqrt(A1*A2 - A3);
     // Area is equivalent to 2 pi sigma^2
@@ -69,5 +69,5 @@
     norm = 0.0;
     for (z = 0.005; z < 50; z += 0.01) {
-	f = 1.0 / (1 + z + pow(z, PAR[7]));
+	f = 1.0 / (1 + z + pow(z, PAR[PM_PAR_7]));
 	norm += f;
     }
@@ -87,15 +87,15 @@
 
     if (flux <= 0) return (1.0);
-    if (PAR[1] <= 0) return (1.0);
-    if (flux >= PAR[1]) return (1.0);
+    if (PAR[PM_PAR_FLUX] <= 0) return (1.0);
+    if (flux >= PAR[PM_PAR_FLUX]) return (1.0);
 
     // if Sx == Sy, sigma = Sx == Sy
-    psF64 sigma = hypot (1.0 / PAR[4], 1.0 / PAR[5]) / sqrt(2.0);
+    psF64 sigma = hypot (1.0 / PAR[PM_PAR_SXX], 1.0 / PAR[PM_PAR_SYY]) / sqrt(2.0);
     psF64 dz = 1.0 / (2.0 * sigma*sigma);
-    psF64 limit = flux / PAR[1];
+    psF64 limit = flux / PAR[PM_PAR_FLUX];
 
     // we can do this much better with intelligent choices here
     for (z = 0.0; z < 20.0; z += dz) {
-	p = pow(z, PAR[7]);
+	p = pow(z, PAR[PM_PAR_7]);
 	f = 1.0 / (1 + z + p);
 	if (f < limit) break;