1 files changed, 83 insertions, 0 deletions
diff --git a/gsl-1.9/rng/vax.c b/gsl-1.9/rng/vax.c
new file mode 100644
index 0000000..8c0f725
--- /dev/null
+++ b/gsl-1.9/rng/vax.c
@@ -0,0 +1,83 @@
+/* rng/vax.c
+ * 
+ * Copyright (C) 1996, 1997, 1998, 1999, 2000 James Theiler, Brian Gough
+ * 
+ * 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.
+ */
+
+#include <config.h>
+#include <stdlib.h>
+#include <gsl/gsl_rng.h>
+
+/* This is the old vax generator MTH$RANDOM. The sequence is,
+
+   x_{n+1} = (a x_n + c) mod m
+
+   with a = 69069, c = 1 and m = 2^32. The seed specifies the initial
+   value, x_1.
+
+   The theoretical value of x_{10001} is 3051034865.
+
+   The period of this generator is 2^32. */
+
+static inline unsigned long int vax_get (void *vstate);
+static double vax_get_double (void *vstate);
+static void vax_set (void *state, unsigned long int s);
+
+typedef struct
+  {
+    unsigned long int x;
+  }
+vax_state_t;
+
+static inline unsigned long int
+vax_get (void *vstate)
+{
+  vax_state_t *state = (vax_state_t *) vstate;
+
+  state->x = (69069 * state->x + 1) & 0xffffffffUL;
+
+  return state->x;
+}
+
+static double
+vax_get_double (void *vstate)
+{
+  return vax_get (vstate) / 4294967296.0 ;
+}
+
+static void
+vax_set (void *vstate, unsigned long int s)
+{
+  vax_state_t *state = (vax_state_t *) vstate;
+
+  /* default seed is 0. The constant term c stops the series from
+     collapsing to 0,0,0,0,0,... */
+
+  state->x = s;
+
+  return;
+}
+
+static const gsl_rng_type vax_type =
+{"vax",                         /* name */
+ 0xffffffffUL,                  /* RAND_MAX */
+ 0,                             /* RAND_MIN */
+ sizeof (vax_state_t),
+ &vax_set,
+ &vax_get,
+ &vax_get_double};
+
+const gsl_rng_type *gsl_rng_vax = &vax_type;