Changeset a0168e8 in sasmodels

Timestamp:

Dec 20, 2016 5:16:46 PM (7 years ago)

Author:

Paul Kienzle <pkienzle@…>

Branches:

master, core_shell_microgels, costrafo411, magnetic_model, ticket-1257-vesicle-product, ticket_1156, ticket_1265_superball, ticket_822_more_unit_tests

Children:

d504bcd

Parents:

56b0435

Message:

code cleanup; require at least one layer

Location:

sasmodels/models

Files:

• lamellar_stack_paracrystal.c (modified) (4 diffs)
• lamellar_stack_paracrystal.py (modified) (1 diff)

sasmodels/models/lamellar_stack_paracrystal.c

@@ -2 +2 @@
 
 */
-double Iq(double qval,
-      double th,
-      double Nlayers, 
-          double davg, 
-          double pd,
-      double sld,
-      double solvent_sld);
-double paraCryst_sn(double ww, double qval, double davg, long Nlayers, double an);
-double paraCryst_an(double ww, double qval, double davg, long Nlayers);
+double paraCryst_sn(double ww, double qval, double davg, int Nlayers, double an);
+double paraCryst_an(double ww, double qval, double davg, int Nlayers);
 
-double Iq(double qval,
-      double th,
-      double Nlayers, 
-          double davg, 
-          double pd,
-      double sld,
-      double solvent_sld)
+static double
+Iq(double qval,
+   double th,
+   double fp_Nlayers,
+   double davg,
+   double pd,
+   double sld,
+   double solvent_sld)
 {
-    
-        double inten,contr,xn;
-        double xi,ww,Pbil,Znq,Snq,an;
-        long n1,n2;
+        //get the fractional part of Nlayers, to determine the "mixing" of N's
+        int n1 = (int)(fp_Nlayers);             //truncate towards zero
+        int n2 = n1 + 1;
+        const double xn = (double)n2 - fp_Nlayers;      //fractional contribution of n1
         
-        contr = sld - solvent_sld;
-        //get the fractional part of Nlayers, to determine the "mixing" of N's
-        
-        n1 = (long)trunc(Nlayers);              //rounds towards zero
-        n2 = n1 + 1;
-        xn = (double)n2 - Nlayers;                      //fractional contribution of n1
-        
-        ww = exp(-qval*qval*pd*pd*davg*davg/2.0);
+        const double ww = exp(-0.5*square(qval*pd*davg));
 
         //calculate the n1 contribution
+        double Znq,Snq,an;
         an = paraCryst_an(ww,qval,davg,n1);
         Snq = paraCryst_sn(ww,qval,davg,n1,an);
-        
+
         Znq = xn*Snq;
         
@@ -52 +40 @@
 //      Zq = (1-ww^2)/(1+ww^2-2*ww*cos(qval*davg))
         
-        xi = th/2.0;            //use 1/2 the bilayer thickness
-        Pbil = (sin(qval*xi)/(qval*xi))*(sin(qval*xi)/(qval*xi));
+        const double xi = th/2.0;               //use 1/2 the bilayer thickness
+        const double Pbil = square(sinc(qval*xi));
         
-        inten = 2.0*M_PI*contr*contr*Pbil*Znq/(qval*qval);
-        inten *= 1.0e-04;
+        const double contr = sld - solvent_sld;
+        const double inten = 2.0*M_PI*contr*contr*Pbil*Znq/(qval*qval);
 //printf("q=%.7e wwm1=%g ww=%.5e an=% 12.5e Snq=% 12.5e Znq=% 12.5e Pbil=% 12.5e\n",qval,wwm1,ww,an,Snq,Znq,Pbil);
-        return(inten);
+        return 1.0e-4*inten;
 }
 
 // functions for the lamellar paracrystal model
 double
-paraCryst_sn(double ww, double qval, double davg, long Nlayers, double an) {
+paraCryst_sn(double ww, double qval, double davg, int Nlayers, double an) {
         
         double Snq;
@@ -69 +57 @@
         Snq = an/( (double)Nlayers*square(1.0+ww*ww-2.0*ww*cos(qval*davg)) );
         
-        return(Snq);
+        return Snq;
 }
 
 double
-paraCryst_an(double ww, double qval, double davg, long Nlayers) {
-        
+paraCryst_an(double ww, double qval, double davg, int Nlayers) {
         double an;
         
@@ -82 +69 @@
         an += 2.0*pow(ww,(Nlayers+1))*cos((double)(Nlayers+1)*qval*davg);
         
-        return(an);
+        return an;
 }
 

sasmodels/models/lamellar_stack_paracrystal.py

@@ -113 +113 @@
 parameters = [["thickness", "Ang", 33.0, [0, inf], "volume",
                "sheet thickness"],
-              ["Nlayers", "", 20, [0, inf], "",
+              ["Nlayers", "", 20, [1, inf], "",
                "Number of layers"],
               ["d_spacing", "Ang", 250., [0.0, inf], "",