1 files changed, 130 insertions, 0 deletions
diff --git a/libm/ldouble/gdtrl.c b/libm/ldouble/gdtrl.c
new file mode 100644
index 000000000..9a41790cb
--- /dev/null
+++ b/libm/ldouble/gdtrl.c
@@ -0,0 +1,130 @@
+/*							gdtrl.c
+ *
+ *	Gamma distribution function
+ *
+ *
+ *
+ * SYNOPSIS:
+ *
+ * long double a, b, x, y, gdtrl();
+ *
+ * y = gdtrl( a, b, x );
+ *
+ *
+ *
+ * DESCRIPTION:
+ *
+ * Returns the integral from zero to x of the gamma probability
+ * density function:
+ *
+ *
+ *                x
+ *        b       -
+ *       a       | |   b-1  -at
+ * y =  -----    |    t    e    dt
+ *       -     | |
+ *      | (b)   -
+ *               0
+ *
+ *  The incomplete gamma integral is used, according to the
+ * relation
+ *
+ * y = igam( b, ax ).
+ *
+ *
+ * ACCURACY:
+ *
+ * See igam().
+ *
+ * ERROR MESSAGES:
+ *
+ *   message         condition      value returned
+ * gdtrl domain        x < 0            0.0
+ *
+ */
+/*							gdtrcl.c
+ *
+ *	Complemented gamma distribution function
+ *
+ *
+ *
+ * SYNOPSIS:
+ *
+ * long double a, b, x, y, gdtrcl();
+ *
+ * y = gdtrcl( a, b, x );
+ *
+ *
+ *
+ * DESCRIPTION:
+ *
+ * Returns the integral from x to infinity of the gamma
+ * probability density function:
+ *
+ *
+ *               inf.
+ *        b       -
+ *       a       | |   b-1  -at
+ * y =  -----    |    t    e    dt
+ *       -     | |
+ *      | (b)   -
+ *               x
+ *
+ *  The incomplete gamma integral is used, according to the
+ * relation
+ *
+ * y = igamc( b, ax ).
+ *
+ *
+ * ACCURACY:
+ *
+ * See igamc().
+ *
+ * ERROR MESSAGES:
+ *
+ *   message         condition      value returned
+ * gdtrcl domain        x < 0            0.0
+ *
+ */
+
+/*							gdtrl()  */
+
+
+/*
+Cephes Math Library Release 2.3:  March, 1995
+Copyright 1984, 1995 by Stephen L. Moshier
+*/
+
+#include <math.h>
+#ifdef ANSIPROT
+extern long double igaml ( long double, long double );
+extern long double igamcl ( long double, long double );
+#else
+long double igaml(), igamcl();
+#endif
+
+long double gdtrl( a, b, x )
+long double a, b, x;
+{
+
+if( x < 0.0L )
+	{
+	mtherr( "gdtrl", DOMAIN );
+	return( 0.0L );
+	}
+return(  igaml( b, a * x )  );
+}
+
+
+
+long double gdtrcl( a, b, x )
+long double a, b, x;
+{
+
+if( x < 0.0L )
+	{
+	mtherr( "gdtrcl", DOMAIN );
+	return( 0.0L );
+	}
+return(  igamcl( b, a * x )  );
+}