Fix minimum lenght in fast azimuthal integration (numpy.bincount)

src/geomtools/powder/misc.py

@@ -2,13 +2,14 @@ import numpy as np
 
 
 def azint_fast(ri, img, mask=None, nan=np.nan):
+    max_ri = np.max(ri)
     if mask is None:
         r, v = ri, img
     else:
         r = ri[~mask]
         v = img[~mask]
-    n = np.bincount(r)
-    rdf = np.bincount(r, weights=v)
+    n = np.bincount(r, minlength=max_ri + 1)
+    rdf = np.bincount(r, weights=v, minlength=max_ri + 1)
     np.divide(rdf, n, where=n > 0, out=rdf)
     rdf[n == 0] = nan
     return rdf