1 files changed, 63 insertions, 0 deletions
diff --git a/gsl-1.9/specfunc/hyperg_2F0.c b/gsl-1.9/specfunc/hyperg_2F0.c
new file mode 100644
index 0000000..022b5cb
--- /dev/null
+++ b/gsl-1.9/specfunc/hyperg_2F0.c
@@ -0,0 +1,63 @@
+/* specfunc/hyperg_2F0.c
+ * 
+ * Copyright (C) 1996, 1997, 1998, 1999, 2000 Gerard Jungman
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+/* Author:  G. Jungman */
+
+#include <config.h>
+#include <gsl/gsl_math.h>
+#include <gsl/gsl_errno.h>
+#include <gsl/gsl_sf_hyperg.h>
+
+#include "error.h"
+#include "hyperg.h"
+
+int
+gsl_sf_hyperg_2F0_e(const double a, const double b, const double x, gsl_sf_result * result)
+{
+  if(x < 0.0) {
+    /* Use "definition" 2F0(a,b,x) = (-1/x)^a U(a,1+a-b,-1/x).
+     */
+    gsl_sf_result U;
+    double pre = pow(-1.0/x, a);
+    int stat_U = gsl_sf_hyperg_U_e(a, 1.0+a-b, -1.0/x, &U);
+    result->val = pre * U.val;
+    result->err = GSL_DBL_EPSILON * fabs(result->val) + pre * U.err;
+    return stat_U;
+  }
+  else if(x == 0.0) {
+    result->val = 1.0;
+    result->err = 0.0;
+    return GSL_SUCCESS;
+  }
+  else {
+    /* Use asymptotic series. ??
+     */
+    /* return hyperg_2F0_series(a, b, x, -1, result, &prec); */
+    DOMAIN_ERROR(result);
+  }
+}
+
+/*-*-*-*-*-*-*-*-*-* Functions w/ Natural Prototypes *-*-*-*-*-*-*-*-*-*-*/
+
+#include "eval.h"
+
+double gsl_sf_hyperg_2F0(const double a, const double b, const double x)
+{
+  EVAL_RESULT(gsl_sf_hyperg_2F0_e(a, b, x, &result));
+}