fixed the selection of unconstrained data

proxtoolbox/ProxOperators/P_M.py

@@ -51,7 +51,7 @@ class P_M_masked(P_M):
         Parameters
         ----------
         config : dict - Dictionary containing the problem configuration. It must contain the following mapping:
-        'M' : array_like - nonegative real FOURIER DOMAIN CONSTRAINT
+        'M' : array_like - non-negative real FOURIER DOMAIN CONSTRAINT
         'data_zeros': array_like, true for masked points, false for non-masked points (where the measurement can be applied).
         """
         super(P_M_masked, self).__init__(config)
@@ -71,5 +71,5 @@ class P_M_masked(P_M):
         """
         fourier_space_iterate = np.fft.fft2(u, axes=None)
         constrained = magproj(fourier_space_iterate, self.M)
-        update = np.where(self.mask, u, constrained)
+        update = np.where(self.mask, fourier_space_iterate, constrained)
         return np.fft.ifft2(update, axes=None)