Changeset 0cfeff4 in sasview for sansmodels/src/sans/models/c_extensions

Timestamp:

Aug 20, 2009 3:32:26 PM (15 years ago)

Author:

Jae Cho <jhjcho@…>

Branches:

master, ESS_GUI, ESS_GUI_Docs, ESS_GUI_batch_fitting, ESS_GUI_bumps_abstraction, ESS_GUI_iss1116, ESS_GUI_iss879, ESS_GUI_iss959, ESS_GUI_opencl, ESS_GUI_ordering, ESS_GUI_sync_sascalc, costrafo411, magnetic_scatt, release-4.1.1, release-4.1.2, release-4.2.2, release_4.0.1, ticket-1009, ticket-1094-headless, ticket-1242-2d-resolution, ticket-1243, ticket-1249, ticket885, unittest-saveload

Children:

fe11a3fa

Parents:

222d75c7

Message:

put kernel directly in this file

File:

• sansmodels/src/sans/models/c_extensions/lamellar.c (modified) (1 diff)

sansmodels/src/sans/models/c_extensions/lamellar.c

@@ -10 +10 @@
 #include <stdlib.h>
 
+/*      LamellarFFX  :  calculates the form factor of a lamellar structure - no S(q) effects included
+                                                -NO polydispersion included
+*/
+double lamellar_kernel(double dp[], double q){
+        double scale,del,sld_bi,sld_sol,contr,bkg;              //local variables of coefficient wave
+        double inten, qval,Pq;
+        double Pi;
+
+
+        Pi = 4.0*atan(1.0);
+        scale = dp[0];
+        del = dp[1];
+        sld_bi = dp[2];
+        sld_sol = dp[3];
+        bkg = dp[4];
+        qval = q;
+        contr = sld_bi -sld_sol;
+
+        Pq = 2.0*contr*contr/qval/qval*(1.0-cos(qval*del));
+
+        inten = 2.0*Pi*scale*Pq/(qval*qval);            //this is now dimensionless...
+
+        inten /= del;                   //normalize by the thickness (in A)
+
+        inten *= 1.0e8;         // 1/A to 1/cm
+
+        return(inten+bkg);
+}
 
 /**