Changeset 1342f6a in sasview

Timestamp:

Mar 29, 2019 10:41:40 AM (6 years ago)

Author:

dirk

Branches:

magnetic_scatt

Children:

73cd800

Parents:

b36e7c7

Message:

Make polarisation efficiency weights consistently the same as in SASmodels

File:

• src/sas/sascalc/calculator/c_extensions/libfunc.c (modified) (3 diffs)

src/sas/sascalc/calculator/c_extensions/libfunc.c

@@ -132 +132 @@
 //      double re_du = 0.0;
 //      double im_du = 0.0;
-//
+//  const double norm=outspin;
+
+
+// The norm is needed to make sure that the scattering cross sections are
+//correctly weighted, such that the sum of spin-resolved measurements adds up to
+// the unpolarised or half-polarised scattering cross section. No intensity weighting
+// needed on the incoming polariser side (assuming that a user), has normalised
+// to the incoming flux with polariser in for SANSPOl and unpolarised beam, respectively.
+
+//if (out_spin < 0.5){norm=1-out_spin;}
+//else{norm=out_spin;}
+
 //      //No mag means no further calculation
 //      if (isangle>0) {
 //              if (m_max < 1.0e-32){
-//                      uu = sqrt((1+in_spin)/2 * (1+out_spin)/2) * uu;
-//                      dd = sqrt((1.0 - in_spin)/2 * (1.0 - out_spin)/2) * dd;
+//                      uu = sqrt(in_spin * out_spin/ norm) * uu ;
+//                      dd = sqrt((1.0 - in_spin) * (1.0 - out_spin)/ norm) * dd ;
 //              }
 //      }
 //      else if (fabs(m_max)< 1.0e-32 && fabs(m_phi)< 1.0e-32 && fabs(m_theta)< 1.0e-32){
-//                      uu = sqrt((1+in_spin)/2 * (1+out_spin)/2) * uu;
-//                      dd = sqrt((1.0 - in_spin)/2 * (1.0 - out_spin)/2) * dd;
+//                      uu = sqrt(in_spin * out_spin/ norm) * uu;
+//                      dd = sqrt((1.0 - in_spin) * (1.0 - out_spin)/ norm) * dd;
 //      } else {
 //
@@ -192 +203 @@
 //
 //              //Find b
-//              uu -= m_sigma_x;
-//              dd += m_sigma_x;
+//              uu += m_sigma_x;
+//              dd -= m_sigma_x;
 //              re_ud = m_sigma_y;
 //              re_du = m_sigma_y;
@@ -199 +210 @@
 //              im_du = -m_sigma_z;
 //
-//              uu = sqrt((1+in_spin) * (1 + out_spin)) * uu;
-//              dd = sqrt((1.0 - in_spin) * (1.0 - out_spin)) * dd;
-//
-//              re_ud = sqrt(in_spin * (1.0 - out_spin)) * re_ud;
-//              im_ud = sqrt(in_spin * (1.0 - out_spin)) * im_ud;
-//              re_du = sqrt((1.0 - in_spin) * out_spin) * re_du;
-//              im_du = sqrt((1.0 - in_spin) * out_spin) * im_du;
+//              uu = sqrt((in_spin) * (out_spin)/ norm) * uu;
+//              dd = sqrt((1.0 - in_spin) * (1.0 - out_spin)/ norm) * dd;
+//
+//              re_ud = sqrt(in_spin * (1.0 - out_spin)/ norm) * re_ud;
+//              im_ud = sqrt(in_spin * (1.0 - out_spin)/ norm) * im_ud;
+//              re_du = sqrt((1.0 - in_spin) * out_spin/ norm) * re_du;
+//              im_du = sqrt((1.0 - in_spin) * out_spin/ norm) * im_du;
 //      }
 //      p_sld->uu = uu;