1 files changed, 59 insertions, 0 deletions
diff --git a/gsl-1.9/doc/examples/fftreal.c b/gsl-1.9/doc/examples/fftreal.c
new file mode 100644
index 0000000..ec34458
--- /dev/null
+++ b/gsl-1.9/doc/examples/fftreal.c
@@ -0,0 +1,59 @@
+#include <stdio.h>
+#include <math.h>
+#include <gsl/gsl_errno.h>
+#include <gsl/gsl_fft_real.h>
+#include <gsl/gsl_fft_halfcomplex.h>
+
+int
+main (void)
+{
+  int i, n = 100;
+  double data[n];
+
+  gsl_fft_real_wavetable * real;
+  gsl_fft_halfcomplex_wavetable * hc;
+  gsl_fft_real_workspace * work;
+
+  for (i = 0; i < n; i++)
+    {
+      data[i] = 0.0;
+    }
+
+  for (i = n / 3; i < 2 * n / 3; i++)
+    {
+      data[i] = 1.0;
+    }
+
+  for (i = 0; i < n; i++)
+    {
+      printf ("%d: %e\n", i, data[i]);
+    }
+  printf ("\n");
+
+  work = gsl_fft_real_workspace_alloc (n);
+  real = gsl_fft_real_wavetable_alloc (n);
+
+  gsl_fft_real_transform (data, 1, n, 
+                          real, work);
+
+  gsl_fft_real_wavetable_free (real);
+
+  for (i = 11; i < n; i++)
+    {
+      data[i] = 0;
+    }
+
+  hc = gsl_fft_halfcomplex_wavetable_alloc (n);
+
+  gsl_fft_halfcomplex_inverse (data, 1, n, 
+                               hc, work);
+  gsl_fft_halfcomplex_wavetable_free (hc);
+
+  for (i = 0; i < n; i++)
+    {
+      printf ("%d: %e\n", i, data[i]);
+    }
+
+  gsl_fft_real_workspace_free (work);
+  return 0;
+}