Index: sasmodels/models/core_shell_ellipsoid.c
===================================================================
--- sasmodels/models/core_shell_ellipsoid.c	(revision 5031ca39a761c97db704b9b8e3a0f211847bb0db)
+++ sasmodels/models/core_shell_ellipsoid.c	(revision 22221346d45e39a667fe231ce7ca5ecfc79b0ac5)
@@ -1,24 +1,24 @@
 double form_volume(double radius_equat_core,
-                   double polar_core,
-                   double equat_shell,
-                   double polar_shell);
+                   double radius_polar_core,
+                   double radius_equat_shell,
+                   double radius_polar_shell);
 double Iq(double q,
           double radius_equat_core,
-          double x_core,
-          double thick_shell,
-          double x_polar_shell,
-          double core_sld,
-          double shell_sld,
-          double solvent_sld);
+          double radius_polar_core,
+          double radius_equat_shell,
+          double radius_polar_shell,
+          double sld_core,
+          double sld_shell,
+          double sld_solvent);
 
 
 double Iqxy(double qx, double qy,
           double radius_equat_core,
-          double x_core,
-          double thick_shell,
-          double x_polar_shell,
-          double core_sld,
-          double shell_sld,
-          double solvent_sld,
+          double radius_polar_core,
+          double radius_equat_shell,
+          double radius_polar_shell,
+          double sld_core,
+          double sld_shell,
+          double sld_solvent,
           double theta,
           double phi);
@@ -26,24 +26,24 @@
 
 double form_volume(double radius_equat_core,
-                   double x_core,
-                   double thick_shell,
-                   double x_polar_shell)
+                   double radius_polar_core,
+                   double radius_equat_shell,
+                   double radius_polar_shell)
 {
-    const double equat_shell = radius_equat_core + thick_shell;
-    const double polar_shell = radius_equat_core*x_core + thick_shell*x_polar_shell;
-    double vol = 4.0*M_PI/3.0*equat_shell*equat_shell*polar_shell;
+    double vol = 4.0*M_PI/3.0*radius_equat_shell*radius_equat_shell*radius_polar_shell;
     return vol;
 }
 
 static double
-core_shell_ellipsoid_xt_kernel(double q,
+core_shell_ellipsoid_kernel(double q,
           double radius_equat_core,
-          double x_core,
-          double thick_shell,
-          double x_polar_shell,
-          double core_sld,
-          double shell_sld,
-          double solvent_sld)
+          double radius_polar_core,
+          double radius_equat_shell,
+          double radius_polar_shell,
+          double sld_core,
+          double sld_shell,
+          double sld_solvent)
 {
+
+    //upper and lower integration limits
     const double lolim = 0.0;
     const double uplim = 1.0;
@@ -51,11 +51,6 @@
     double summ = 0.0;	 //initialize intergral
 
-    const double delpc = core_sld - shell_sld; //core - shell
-    const double delps = shell_sld - solvent_sld; //shell - solvent
-
-
-    const double polar_core = radius_equat_core*x_core;
-    const double equat_shell = radius_equat_core + thick_shell;
-    const double polar_shell = radius_equat_core*x_core + thick_shell*x_polar_shell;
+    const double delpc = sld_core - sld_shell;    //core - shell
+    const double delps = sld_shell - sld_solvent; //shell - solvent
 
     for(int i=0;i<N_POINTS_76;i++) {
@@ -63,7 +58,7 @@
         double yyy = Gauss76Wt[i] * gfn4(zi,
                                   radius_equat_core,
-                                  polar_core,
-                                  equat_shell,
-                                  polar_shell,
+                                  radius_polar_core,
+                                  radius_equat_shell,
+                                  radius_polar_shell,
                                   delpc,
                                   delps,
@@ -73,4 +68,5 @@
 
     double answer = (uplim-lolim)/2.0*summ;
+
     //convert to [cm-1]
     answer *= 1.0e-4;
@@ -80,12 +76,12 @@
 
 static double
-core_shell_ellipsoid_xt_kernel_2d(double q, double q_x, double q_y,
+core_shell_ellipsoid_kernel_2d(double q, double q_x, double q_y,
           double radius_equat_core,
-          double x_core,
-          double thick_shell,
-          double x_polar_shell,
-          double core_sld,
-          double shell_sld,
-          double solvent_sld,
+          double radius_polar_core,
+          double radius_equat_shell,
+          double radius_polar_shell,
+          double sld_core,
+          double sld_shell,
+          double sld_solvent,
           double theta,
           double phi)
@@ -95,10 +91,11 @@
     phi = phi * M_PI_180;
 
+
     // ellipsoid orientation, the axis of the rotation is consistent with the ploar axis.
     const double cyl_x = cos(theta) * cos(phi);
     const double cyl_y = sin(theta);
 
-    const double sldcs = core_sld - shell_sld;
-    const double sldss = shell_sld- solvent_sld;
+    const double sldcs = sld_core - sld_shell;
+    const double sldss = sld_shell- sld_solvent;
 
     // Compute the angle btw vector q and the
@@ -106,15 +103,10 @@
     const double cos_val = cyl_x*q_x + cyl_y*q_y;
 
-    const double polar_core = radius_equat_core*x_core;
-    const double equat_shell = radius_equat_core + thick_shell;
-    const double polar_shell = radius_equat_core*x_core + thick_shell*x_polar_shell;
-
-    // Call the IGOR library function to get the kernel:
-    // MUST use gfn4 not gf2 because of the def of params.
+    // Call the IGOR library function to get the kernel: MUST use gfn4 not gf2 because of the def of params.
     double answer = gfn4(cos_val,
                   radius_equat_core,
-                  polar_core,
-                  equat_shell,
-                  polar_shell,
+                  radius_polar_core,
+                  radius_equat_shell,
+                  radius_polar_shell,
                   sldcs,
                   sldss,
@@ -129,19 +121,19 @@
 double Iq(double q,
           double radius_equat_core,
-          double x_core,
-          double thick_shell,
-          double x_polar_shell,
-          double core_sld,
-          double shell_sld,
-          double solvent_sld)
+          double radius_polar_core,
+          double radius_equat_shell,
+          double radius_polar_shell,
+          double sld_core,
+          double sld_shell,
+          double sld_solvent)
 {
-    double intensity = core_shell_ellipsoid_xt_kernel(q,
+    double intensity = core_shell_ellipsoid_kernel(q,
            radius_equat_core,
-           x_core,
-           thick_shell,
-           x_polar_shell,
-           core_sld,
-           shell_sld,
-           solvent_sld);
+           radius_polar_core,
+           radius_equat_shell,
+           radius_polar_shell,
+           sld_core,
+           sld_shell,
+           sld_solvent);
 
     return intensity;
@@ -151,10 +143,10 @@
 double Iqxy(double qx, double qy,
           double radius_equat_core,
-          double x_core,
-          double thick_shell,
-          double x_polar_shell,
-          double core_sld,
-          double shell_sld,
-          double solvent_sld,
+          double radius_polar_core,
+          double radius_equat_shell,
+          double radius_polar_shell,
+          double sld_core,
+          double sld_shell,
+          double sld_solvent,
           double theta,
           double phi)
@@ -162,12 +154,12 @@
     double q;
     q = sqrt(qx*qx+qy*qy);
-    double intensity = core_shell_ellipsoid_xt_kernel_2d(q, qx/q, qy/q,
+    double intensity = core_shell_ellipsoid_kernel_2d(q, qx/q, qy/q,
                        radius_equat_core,
-                       x_core,
-                       thick_shell,
-                       x_polar_shell,
-                       core_sld,
-                       shell_sld,
-                       solvent_sld,
+                       radius_polar_core,
+                       radius_equat_shell,
+                       radius_polar_shell,
+                       sld_core,
+                       sld_shell,
+                       sld_solvent,
                        theta,
                        phi);
