Changeset 2c74c11 in sasmodels for sasmodels/models/two_power_law.py

Timestamp:

Jul 24, 2016 10:56:45 PM (8 years ago)

Author:

Paul Kienzle <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:

a4280bd

Parents:

f1765a2

Message:

implicit Iqxy; fix divide by 0 for q=0

File:

• sasmodels/models/two_power_law.py (modified) (2 diffs)

sasmodels/models/two_power_law.py

@@ -44 +44 @@
 """
 
-from numpy import power
-from numpy import sqrt
-from numpy import inf
-from numpy import concatenate
+from numpy import inf, power, empty, errstate
 
 name = "two_power_law"
@@ -92 +89 @@
     :return:                    Calculated intensity
     """
-
-    #Two sub vectors are created to treat crossover values
-    q_lower = q[q <= crossover]
-    q_upper = q[q > crossover]
-    coefficent_2 = coefficent_1*power(crossover, -1.0*power_1)/power(crossover, -1.0*power_2)
-    intensity_lower = coefficent_1*power(q_lower, -1.0*power_1)
-    intensity_upper = coefficent_2*power(q_upper, -1.0*power_2)
-    intensity = concatenate((intensity_lower, intensity_upper), axis=0)
-
-    return intensity
+    iq = empty(q.shape, 'd')
+    idx = (q <= crossover)
+    with errstate(divide='ignore'):
+        coefficent_2 = coefficent_1 * power(crossover, power_2 - power_1)
+        iq[idx] = coefficent_1 * power(q[idx], -power_1)
+        iq[~idx] = coefficent_2 * power(q[~idx], -power_2)
+    return iq
 
 Iq.vectorized = True  # Iq accepts an array of q values
-
-def Iqxy(qx, qy, *args):
-    """
-    :param qx:   Input q_x-value
-    :param qy:   Input q_y-value
-    :param args: Remaining arguments
-    :return:     2D-Intensity
-    """
-
-    return Iq(sqrt(qx**2 + qy**2), *args)
-
-Iqxy.vectorized = True  # Iqxy accepts an array of qx, qy values
 
 demo = dict(scale=1, background=0.0,