Changeset 44f39a2 in sasmodels

Timestamp:

Mar 20, 2016 5:48:20 AM (8 years ago)

Author:

wojciech

Branches:

master, core_shell_microgels, costrafo411, magnetic_model, release_v0.94, release_v0.95, ticket-1257-vesicle-product, ticket_1156, ticket_1265_superball, ticket_822_more_unit_tests

Children:

3044216

Parents:

a10da8b

Message:

A few comments added

File:

• sasmodels/kernel_iq.c (modified) (3 diffs)

sasmodels/kernel_iq.c

@@ -62 +62 @@
 calculator treats the parameter set as one long vector.
 
+Let's assume we have 6 polydisperse parameters
+0 : sld_solvent {s1 = constant}
+1: sld_material {s2 = constant}
+2: radius   {r = vector of 10pts}
+3: lenghth {l = vector of 30pts}
+4: background {b = constant}
+5: scale {s = constant}
+
 The polydisperse parameters are stored in as an array of parameter
 indices, one for each polydisperse parameter, stored in pd_par[n].
+For the above mentioned expample that will give pd_par = {3, 2, x, x},
+where x stands for abitrary number and 3 corresponds to longest parameter (lenght).
 Non-polydisperse parameters do not appear in this array. Each polydisperse
-parameter has a weight vector whose length is stored in pd_length[n].
-The weights are stored in a contiguous vector of weights for all
-parameters, with the starting position for the each parameter stored
-in pd_offset[n].  The values corresponding to the weights are stored
-together in a separate weights[] vector, with offset stored in
-par_offset[pd_par[n]]. Polydisperse parameters should be stored in
-decreasing order of length for highest efficiency.
+parameter has a weight vector whose length is stored in pd_length[n],
+In our case pd_length = {30,10,0,0}. The weights are stored in
+a contiguous vector of weights for all parameters, with the starting position
+for the each parameter stored in pd_offset[n] (pd_offset = {10,0,x,x}.
+The values corresponding to the weights are stored together in a
+separate weights[] vector, with offset stored in par_offset[pd_par[n]].
+In the above mentioned example weight = {r0, .., r9, l0, .., l29}.
+Polydisperse parameters should be stored in decreasing order of length
+for highest efficiency.
 
 We limit the number of polydisperse dimensions to MAX_PD (currently 4).
@@ -85 +97 @@
 separate value for the sld.  The caller must provide a coordination table
 for each parameter containing the value for each parameter given the
-value of the polydisperse parameters v1, v2, etc.   The tables for each
+value of the polydisperse parameters v1, v2, etc.  The tables for each
 parameter are arranged contiguously in a vector, with offset[k] giving the
 starting location of parameter k in the vector.  Each parameter defines
@@ -266 +278 @@
         result[i] *= norm_vol[i]/vol[i];
       }
-      //TODO: Ask Richard if scale and background may be corridanted parameters
-      result[i] = scale*result[i]/norm[i]+background;
+        result[i] = scale*result[i]/norm[i]+background;
     }
   }