1 files changed, 183 insertions, 0 deletions
diff --git a/gsl-1.9/fft/real_init.c b/gsl-1.9/fft/real_init.c
new file mode 100644
index 0000000..75d89e8
--- /dev/null
+++ b/gsl-1.9/fft/real_init.c
@@ -0,0 +1,183 @@
+/* fft/real_init.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.
+ */
+
+TYPE(gsl_fft_real_wavetable) *
+FUNCTION(gsl_fft_real_wavetable,alloc) (size_t n)
+{
+  int status;
+  size_t i;
+  size_t n_factors;
+  size_t t, product, product_1, q;
+  double d_theta;
+
+  TYPE(gsl_fft_real_wavetable) * wavetable;
+
+  if (n == 0)
+    {
+      GSL_ERROR_VAL ("length n must be positive integer", GSL_EDOM, 0);
+    }
+
+  wavetable = (TYPE(gsl_fft_real_wavetable) *) 
+    malloc(sizeof(TYPE(gsl_fft_real_wavetable)));
+
+  if (wavetable == NULL)
+    {
+      GSL_ERROR_VAL ("failed to allocate struct", GSL_ENOMEM, 0);
+    }
+
+  if (n == 1) 
+    {
+      wavetable->trig = 0;
+    }
+  else
+    {
+      wavetable->trig = (TYPE(gsl_complex) *) 
+        malloc ((n / 2) * sizeof (TYPE(gsl_complex)));
+      
+      if (wavetable->trig == NULL)
+        {
+          /* error in constructor, prevent memory leak */
+          
+          free(wavetable) ; 
+
+          GSL_ERROR_VAL ("failed to allocate trigonometric lookup table", 
+                            GSL_ENOMEM, 0);
+        }
+    }
+
+  wavetable->n = n;
+
+  status = fft_real_factorize (n, &n_factors, wavetable->factor);
+
+  if (status)
+    {
+      /* error in constructor, prevent memory leak */
+      
+      free(wavetable->trig);
+      free(wavetable) ; 
+
+      GSL_ERROR_VAL ("factorization failed", GSL_EFACTOR, 0);
+    }
+
+  wavetable->nf = n_factors;
+
+  d_theta = 2.0 * M_PI / ((double) n);
+
+  t = 0;
+  product = 1;
+  for (i = 0; i < wavetable->nf; i++)
+    {
+      size_t j;
+      const size_t factor = wavetable->factor[i];
+      wavetable->twiddle[i] = wavetable->trig + t;
+      product_1 = product;      /* product_1 = p_(i-1) */
+      product *= factor;
+      q = n / product;
+
+      for (j = 1; j < factor; j++)
+        {
+          size_t k;
+          size_t m = 0;
+          for (k = 1; k < (product_1 + 1) / 2; k++)
+            {
+              double theta;
+              m = m + j * q;
+              m = m % n;
+              theta = d_theta * m;      /*  d_theta*j*k*q */
+              GSL_REAL(wavetable->trig[t]) = cos (theta);
+              GSL_IMAG(wavetable->trig[t]) = sin (theta);
+
+              t++;
+            }
+        }
+    }
+
+  if (t > (n / 2))
+    {
+      /* error in constructor, prevent memory leak */
+
+      free(wavetable->trig);
+      free(wavetable) ; 
+
+      GSL_ERROR_VAL ("overflowed trigonometric lookup table", 
+                        GSL_ESANITY, 0);
+    }
+
+  return wavetable;
+}
+
+TYPE(gsl_fft_real_workspace) *
+FUNCTION(gsl_fft_real_workspace,alloc) (size_t n)
+{
+  TYPE(gsl_fft_real_workspace) * workspace;
+
+  if (n == 0)
+    {
+      GSL_ERROR_VAL ("length n must be positive integer", GSL_EDOM, 0);
+    }
+
+  workspace = (TYPE(gsl_fft_real_workspace) *) 
+    malloc(sizeof(TYPE(gsl_fft_real_workspace)));
+
+  if (workspace == NULL)
+    {
+      GSL_ERROR_VAL ("failed to allocate struct", GSL_ENOMEM, 0);
+    }
+
+  workspace->n = n;
+
+  workspace->scratch = (BASE *) malloc (n * sizeof (BASE));
+
+  if (workspace->scratch == NULL)
+    {
+      /* error in constructor, prevent memory leak */
+      
+      free(workspace) ; 
+
+      GSL_ERROR_VAL ("failed to allocate scratch space", GSL_ENOMEM, 0);
+    }
+
+  return workspace;
+}
+
+
+
+void
+FUNCTION(gsl_fft_real_wavetable,free) (TYPE(gsl_fft_real_wavetable) * wavetable)
+{
+
+  /* release trigonometric lookup tables */
+
+  free (wavetable->trig);
+  wavetable->trig = NULL;
+
+  free (wavetable) ;
+}
+
+void
+FUNCTION(gsl_fft_real_workspace,free) (TYPE(gsl_fft_real_workspace) * workspace)
+{
+
+  /* release scratch space */
+
+  free (workspace->scratch);
+  workspace->scratch = NULL;
+
+  free (workspace) ;
+}