Merge pull request #931 from oesteban/fix/zero-division-warning

[FIX] RuntimeWarning: divide by zero encountered in float_scalars
nipreps · Jan 11, 2018 · d343a73 · d343a73
2 parents 10ff73e + daa2f99
commit d343a73
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diff --git a/CHANGES.rst b/CHANGES.rst
@@ -1,6 +1,7 @@
 Next release
 ============
 
+* [FIX] RuntimeWarning: divide by zero encountered in float_scalars (#931).
 * [FIX] INU correction before merging several T1w (#925).
 
 

diff --git a/fmriprep/interfaces/freesurfer.py b/fmriprep/interfaces/freesurfer.py
@@ -356,7 +356,9 @@ def grow_mask(anat, aseg, ants_segs=None, ww=7, zval=2.0, bw=4):
             pixel[2] - ww:pixel[2] + ww
         ]
         if np.any(window > 0):
-            zstat = abs(anat[tuple(pixel)] - window[window > 0].mean()) / window[window > 0].std()
+            mu = window[window > 0].mean()
+            sigma = min(window[window > 0].std(), 1.e-5)
+            zstat = abs(anat[tuple(pixel)] - mu) / sigma
             refined[tuple(pixel)] = int(zstat < zval)
 
     refined = sim.binary_opening(refined, selem)