Changeset 41b1edd in sasmodels

Timestamp:

Dec 20, 2016 4:50:50 PM (8 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:

8c92abb

Parents:

e9b0ef3

Message:

round to nearest number of layers; tweak equation layout and docs

Location:

sasmodels/models

Files:

• multilayer_vesicle.c (modified) (2 diffs)
• multilayer_vesicle.py (modified) (4 diffs)

sasmodels/models/multilayer_vesicle.c

@@ -7 +7 @@
           double sld_solvent,
           double sld,
-          double n_pairs)
+          int n_pairs)
 {
     //calculate with a loop, two shells at a time
@@ -47 +47 @@
           double sld_solvent,
           double sld,
-          double n_pairs)
+          double fp_n_pairs)
 {
+    int n_pairs = (int)(fp_n_pairs + 0.5);
     return multilayer_vesicle_kernel(q,
            volfraction,

sasmodels/models/multilayer_vesicle.py

@@ -19 +19 @@
 
 .. math::
+    P(q) = \text{scale} \cdot \frac{V_f}{V_t} F^2(q) + \text{background}
 
-    P(q) = \frac{\text{scale.volfraction}}{V_t} F^2(q) + \text{background}
-
-where
+for
 
 .. math::
+    F(q) = (\rho_\text{shell}-\rho_\text{solv}) \sum_{i=1}^{n_\text{pairs}}
+        \left[
+          3V(R_i)\frac{\sin(qR_i)-qR_i\cos(qR_i)}{(qR_i)^3} \\
+          - 3V(R_i+t_s)\frac{\sin(q(R_i+t_s))-q(R_i+t_s)\cos(q(R_i+t_s))}{(q(R_i+t_s))^3}
+        \right]
 
-     F(q) = (\rho_{shell}-\rho_{solv}) \sum_{i=1}^{n\_pairs} \left[
-     3V(R_i)\frac{\sin(qR_i)-qR_i\cos(qR_i)}{(qR_i)^3} \\
-      - 3V(R_i+t_s)\frac{\sin(q(R_i+t_s))-q(R_i+t_s)\cos(q(R_i+t_s))}{(q(R_i+t_s))^3}
-     \right]
+and
 
+.. math::
+     R_i = r_c + (i-1)(t_s + t_w)
 
-where $R_i = r_c + (i-1)(t_s + t_w)$
-   
-where $V_t$ is the volume of the whole particle, $V(R)$ is the volume of a sphere
-of radius $R$, $r_c$ is the radius of the core, $\rho_{shell}$ is the scattering length 
-density of a shell, $\rho_{solv}$ is the scattering length density of the solvent.
+where $V_f$ is the volume fraction of particles, $V_t$ is the volume of the
+whole particle, $V(r)$ is the volume of a sphere of radius $r$, $r_c$ is the
+radius of the core, $\rho_\text{shell}$ is the scattering length density of a
+shell, $\rho_\text{solv}$ is the scattering length density of the solvent.
 
+The outer most radius, $r_o = R_n + t_s$, is used for both the volume fraction
+normalization and for the effective radius for *S(Q)* when $P(Q) * S(Q)$
+is applied.
 
 The 2D scattering intensity is the same as 1D, regardless of the orientation
@@ -45 +50 @@
 
     q = \sqrt{q_x^2 + q_y^2}
-
-
-The outer most radius
-
-$radius + n\_pairs * thick\_shell + (n\_pairs- 1) * thick\_solvent$
-
-is used for both the volume fraction normalization and for the 
-effective radius for *S(Q)* when $P(Q) * S(Q)$ is applied.
 
 For information about polarised and magnetic scattering, see
@@ -70 +67 @@
 **Author:** NIST IGOR/DANSE **on:** pre 2010
 
-**Last Modified by:** Piotr Rozyczko**on:** Feb 24, 2016
+**Last Modified by:** Piotr Rozyczko **on:** Feb 24, 2016
 
 **Last Reviewed by:** Paul Butler **on:** March 20, 2016
@@ -109 +106 @@
 source = ["lib/sph_j1c.c", "multilayer_vesicle.c"]
 
+# TODO: the following line does nothing
 polydispersity = ["radius", "n_pairs"]