Changeset fba9ca0 in sasmodels for sasmodels/special.py

Timestamp:

Oct 12, 2018 3:50:37 PM (6 years ago)

Author:

Paul Kienzle <pkienzle@…>

Branches:

master, core_shell_microgels, magnetic_model, ticket-1257-vesicle-product, ticket_1156, ticket_1265_superball, ticket_822_more_unit_tests

Children:

57c609b

Parents:

353e899

Message:

add gammaln and gammainc to the opencl math library

File:

• sasmodels/special.py (modified) (2 diffs)

sasmodels/special.py

@@ -113 +113 @@
         The standard math function, tgamma(x) is unstable for $x < 1$
         on some platforms.
+
+    sas_gammaln(x):
+        log gamma function sas_gammaln\ $(x) = \log \Gamma(|x|)$.
+
+        The standard math function, lgamma(x), is incorrect for single
+        precision on some platforms.
+
+    sas_gammainc(a, x), sas_gammaincc(a, x):
+        Incomplete gamma function
+        sas_gammainc\ $(a, x) = \int_0^x t^{a-1}e^{-t}\,dt / \Gamma(a)$
+        and complementary incomplete gamma function
+        sas_gammaincc\ $(a, x) = \int_x^\infty t^{a-1}e^{-t}\,dt / \Gamma(a)$
 
     sas_erf(x), sas_erfc(x):
@@ -207 +219 @@
 from numpy import pi, nan, inf
 from scipy.special import gamma as sas_gamma
+from scipy.special import gammaln as sas_gammaln
+from scipy.special import gammainc as sas_gammainc
+from scipy.special import gammaincc as sas_gammaincc
 from scipy.special import erf as sas_erf
 from scipy.special import erfc as sas_erfc