Changeset 10576d1 in sasmodels

Timestamp:

Feb 16, 2015 6:25:36 PM (9 years ago)

Author:

pkienzle

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:

d547f16

Parents:

250fa25

Message:

add hankel function and sesans demo (not yet integrated with models)

Files:

• sasmodels/hankel.py (added)
• sasmodels/models/spherepy.py (modified) (2 diffs)
• sesansdemo.py (added)

sasmodels/models/spherepy.py

@@ -58 +58 @@
 """
 
-from numpy import pi, inf, sin, cos, sqrt
+import numpy as np
+from numpy import pi, inf, sin, cos, sqrt, exp, log
 
 name = "sphere"
@@ -105 +106 @@
 Iqxy.vectorized = True
 
+def sesans(z, sld, solvent_sld, radius):
+    """
+    Calculate SESANS-correlation function for a solid sphere.
+
+    Wim Bouwman after formulae Timofei Kruglov J.Appl.Cryst. 2003 article
+    """
+    d = z/radius
+    g = np.zeros_like(z)
+    g[d==0] = 1.
+    low = ((d > 0) & (d < 2))
+    dlow = d[low]
+    dlow2 = dlow**2
+    g[low] = sqrt(1-dlow2/4.)*(1+dlow2/8.) + dlow2/2.*(1-dlow2/16.)*log(dlow/(2.+sqrt(4.-dlow2)))
+    return g
+sesans.vectorized = True
+
 def ER(radius):
     return radius