diff --git a/processing/post/addCurl.py b/processing/post/addCurl.py
index 484af9677..b4dd465a9 100755
--- a/processing/post/addCurl.py
+++ b/processing/post/addCurl.py
@@ -27,7 +27,6 @@ def curlFFT(geomdim,field):
   n = np.array(np.shape(field)[3:]).prod()                                                           # data size
 
   field_fourier = np.fft.rfftn(field,axes=(0,1,2),s=shapeFFT)
-  curl_fourier  = np.empty(field_fourier.shape,'c16')
 
   # differentiation in Fourier space
   TWOPIIMG = 2.0j*np.pi
diff --git a/processing/post/addDivergence.py b/processing/post/addDivergence.py
index 31a18f8e1..2d6af2036 100755
--- a/processing/post/addDivergence.py
+++ b/processing/post/addDivergence.py
@@ -27,7 +27,6 @@ def divFFT(geomdim,field):
   n = np.array(np.shape(field)[3:]).prod()                                                           # data size
 
   field_fourier = np.fft.rfftn(field,axes=(0,1,2),s=shapeFFT)
-  div_fourier   = np.empty(field_fourier.shape[0:len(np.shape(field))-1],'c16')
 
   # differentiation in Fourier space
   TWOPIIMG = 2.0j*np.pi
diff --git a/processing/post/addGradient.py b/processing/post/addGradient.py
index bfadb578e..252b72eb8 100755
--- a/processing/post/addGradient.py
+++ b/processing/post/addGradient.py
@@ -27,7 +27,6 @@ def gradFFT(geomdim,field):
   n = np.array(np.shape(field)[3:]).prod()                                                           # data size
 
   field_fourier = np.fft.rfftn(field,axes=(0,1,2),s=shapeFFT)
-  grad_fourier  = np.empty(field_fourier.shape+(3,),'c16')
 
   # differentiation in Fourier space
   TWOPIIMG = 2.0j*np.pi