1 files changed, 115 insertions, 0 deletions
diff --git a/gsl-1.9/histogram/test2d_resample.c b/gsl-1.9/histogram/test2d_resample.c
new file mode 100644
index 0000000..4df207f
--- /dev/null
+++ b/gsl-1.9/histogram/test2d_resample.c
@@ -0,0 +1,115 @@
+/* histogram/test2d_resample.c
+ * 
+ * Copyright (C) 1996, 1997, 1998, 1999, 2000 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 <math.h>
+#include <gsl/gsl_histogram2d.h>
+#include <gsl/gsl_test.h>
+#include <gsl/gsl_ieee_utils.h>
+
+#include "urand.c"
+
+void
+test2d_resample (void)
+{
+  size_t i, j;
+  int status = 0;
+  double total = 0;
+  size_t N = 200000;
+
+  gsl_histogram2d *h;
+
+  gsl_ieee_env_setup ();
+
+  h = gsl_histogram2d_calloc_uniform (10, 10, 0.0, 1.0, 0.0, 1.0);
+
+  for (i = 0; i < 10; i++)
+    {
+      for (j = 0; j < 10; j++)
+        {
+          double w = 10.0 * i + j;
+          total += w;
+          gsl_histogram2d_accumulate (h, 0.1 * i, 0.1 * i, w);
+        }
+    }
+
+  {
+    gsl_histogram2d_pdf *p = gsl_histogram2d_pdf_alloc (10,10);
+
+    gsl_histogram2d *hh = gsl_histogram2d_calloc_uniform (20, 20,
+                                                          0.0, 1.0,
+                                                          0.0, 1.0);
+
+    gsl_histogram2d_pdf_init (p, h);
+
+    for (i = 0; i < N; i++)
+      {
+        double u = urand();
+        double v = urand();
+        double x, y;
+        status = gsl_histogram2d_pdf_sample (p, u, v, &x, &y);
+        status = gsl_histogram2d_increment (hh, x, y);
+      }
+
+    status = 0;
+    for (i = 0; i < 20; i++)
+      {
+        for (j = 0; j < 20; j++)
+          {
+            double z = 4 * total * gsl_histogram2d_get (hh, i, j) / (double) N;
+            size_t k1, k2;
+            double ya;
+            double x, xmax, y, ymax;
+
+            gsl_histogram2d_get_xrange (hh, i, &x, &xmax);
+            gsl_histogram2d_get_yrange (hh, j, &y, &ymax);
+
+            gsl_histogram2d_find (h, x, y, &k1, &k2);
+            ya = gsl_histogram2d_get (h, k1, k2);
+
+            if (ya == 0)
+              {
+                if (z != 0)
+                  {
+                    status = 1;
+                    printf ("(%d,%d): %g vs %g\n", (int)i, (int)j, z, ya);
+                  }
+              }
+            else
+              {
+                double err = 1 / sqrt (gsl_histogram2d_get (hh, i, j));
+                double sigma = fabs ((z - ya) / (ya * err));
+                if (sigma > 3)
+                  {
+                    status = 1;
+                    printf ("%g vs %g err=%g sigma=%g\n", z, ya, err, sigma);
+                  }
+              }
+          }
+      }
+
+    gsl_histogram2d_pdf_free (p) ;
+    gsl_histogram2d_free (hh) ;
+    
+    gsl_test (status, "gsl_histogram2d_pdf_sample within statistical errors");
+  }
+
+  gsl_histogram2d_free (h) ;
+}