added sf_gamma

2 files changed, 11 insertions, 1 deletions

diff --git a/lib/GSL/Special.hs b/lib/GSL/Special.hs
index 643c499..fec96eb 100644
--- a/lib/GSL/Special.hs
+++ b/lib/GSL/Special.hs
@@ -19,7 +19,8 @@ module GSL.Special (
     erf,
     erf_Z,
     bessel_J0_e,
-    exp_e10_e
+    exp_e10_e,
+    gamma
 )
 where
 
@@ -45,6 +46,14 @@ foreign import ccall "gsl-aux.h gsl_sf_erf" erf :: Double -> Double
 -}
 foreign import ccall "gsl-aux.h gsl_sf_erf_Z" erf_Z :: Double -> Double
 
+{- | The gamma function (/gsl_sf_gamma/), described in <http://www.gnu.org/software/gsl/manual/html_node/Gamma-Functions.html>
+
+>> gamma 5
+>24.0
+
+-}
+foreign import ccall "gsl-aux.h gsl_sf_gamma" gamma :: Double -> Double
+
 ----------------------------------------------------------------
 -- the sf_result struct is equivalent to an array of two doubles
 
diff --git a/lib/GSL/gsl-aux.h b/lib/GSL/gsl-aux.h
index 89bd75e..2be07c1 100644
--- a/lib/GSL/gsl-aux.h
+++ b/lib/GSL/gsl-aux.h
@@ -61,6 +61,7 @@ int deriv(int code, double f(double, void*), double x, double h, double * result
 
 double gsl_sf_erf(double);
 double gsl_sf_erf_Z(double);
+double gsl_sf_gamma(double);
 
 int gsl_sf_bessel_J0_e(double, double*); // hmmm...
 int gsl_sf_exp_e10_e(double, double*);   // HMMMMM...