corrected check if mask has been passed in get_parameters

Author: mario

code/python/cni_toolbox/HGR.py

@@ -179,7 +179,7 @@ def get_parameters(self, n_batch = 10000,
 
         print('\nestimating pRF parameters')
 
-        if mask == None:
+        if np.size(mask) == 0:
             mask = np.ones(self.n_voxels).astype(bool)
         idx = np.arange(self.n_voxels)
         idx = idx(mask)