GammaRegularized: fix for large argument bug

13 years ago · e97387dc0b
1 changed files with 2 additions and 2 deletions
--- a/src/Numerics/SpecialFunctions/Gamma.cs
+++ b/src/Numerics/SpecialFunctions/Gamma.cs
@ -181,7 +181,7 @@ namespace MathNet.Numerics
            double ax = a * Math.Log(x) - x - GammaLn(a);
            if (ax < -709.78271289338399)
            {
-                return 0;
+                return a < x ? 0d : 1d;
            }

            ax = Math.Exp(ax);
@ -291,7 +291,7 @@ namespace MathNet.Numerics
            double ax = (a * Math.Log(x)) - x - GammaLn(a);
            if (ax < -709.78271289338399)
            {
-                return 1d;
+                return a < x ? 1d : 0d;
            }

            if (x <= 1 || x <= a)