Changeset 8d97277 in sasview for sansmodels

Timestamp:

Mar 31, 2010 1:36:22 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:

7dca26e

Parents:

f10063e

Message:

changed scale definition to be uncorrelated with length: due to the recent NIST code changes

File:

• sansmodels/src/sans/models/DABModel.py (modified) (3 diffs)

sansmodels/src/sans/models/DABModel.py

@@ -13 +13 @@
         Class that evaluates a DAB model.
         
-        F(x) = scale/( 1 + (x*L)^2 )^(2) + background
+        F(x) = scale*(L^3)/( 1 + (x*L)^2 )^(2) + background
         
         The model has three parameters: 
@@ -29 +29 @@
         ## Name of the model
         self.name = "DAB_Model"
-        self.description="""F(x) = scale/( 1 + (x*L)^2 )^(2) + background
+        self.description="""F(x) = scale*(L^3)/( 1 + (x*L)^2 )^(2) + background
         
         The model has three parameters: 
@@ -50 +50 @@
     def _DAB(self, x):
         """
-            Evaluate  F(x) = scale/( 1 + (x*L)^2 )^(2) + background
+            Evaluate  F(x) = (scale*L^3)/( 1 + (x*L)^2 )^(2) + background
            
         """
-        return self.params['scale']/math.pow(( 1 + math.pow(x * self.params['length'],2)),2) \
+        # According to SRK (Igor/NIST code: 6 JUL 2009  changed definition of 'scale' to be uncorrelated with 'length')
+        return self.params['scale']*math.pow(self.params['length'],3)/math.pow(( 1 + math.pow(x * self.params['length'],2)),2) \
          + self.params['background']