Merge pull request #1668 from leftaroundabout/regression/pyfftw-0.13-normalisation-convention

Fix Fourier normalisation that was changed by PyFFTW-0.13

Author: leftaroundabout

odl/trafos/backends/pyfftw_bindings.py

@@ -203,7 +203,10 @@ def pyfftw_call(array_in, array_out, direction='forward', axes=None,
     else:
         fftw_plan = fftw_plan_in
 
-    fftw_plan(array_in, array_out, normalise_idft=normalise_idft)
+    if not normalise_idft and direction=='forward':
+        fftw_plan(array_in, array_out, normalise_idft=True)
+    else:
+        fftw_plan(array_in, array_out, normalise_idft=normalise_idft)
 
     if wexport:
         try:

odl/trafos/fourier.py

@@ -675,7 +675,8 @@ def _call_pyfftw(self, x, out, **kwargs):
             halfcomplex=self.halfcomplex, planning_effort=effort,
             fftw_plan=self._fftw_plan, normalise_idft=True)
 
-        # Need to normalize for 'forward', no way to force pyfftw
+        # Need to normalize for 'forward', pyfftw before version 0.13
+        # does not offer a way to do this.
         if self.sign == '-':
             out /= np.prod(np.take(self.domain.shape, self.axes))