BUG: Fix nanargmax/nanargmin for 1D integer arguments

These functions should return the argument of the *first* max/min value (like numpy). This was not the case in the current release, since there is special logic for 1D integer arrays (they are iterated through forwards instead of backwards like all other array types).
pydata · Jan 10, 2014 · 79a5cba · 79a5cba
1 parent d46d268
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diff --git a/RELEASE.rst b/RELEASE.rst
@@ -11,6 +11,9 @@ Bottleneck 0.8.0
 
 *Release date: Not yet released, in development*
 
+**Bug fixes**
+
+- nanargmax/nanargmin wrong for redundant max/min values in 1d int arrays
 
 Older versions
 ==============

diff --git a/bottleneck/src/template/func/nanargmax.py b/bottleneck/src/template/func/nanargmax.py
@@ -98,7 +98,7 @@ def NAME_NDIMd_DTYPE_axisAXIS(np.ndarray[np.DTYPE_t, ndim=NDIM] a):
     amax = MINDTYPE
     for iINDEX0 in range(nINDEX0):
         ai = a[INDEXALL]
-        if ai >= amax:
+        if ai > amax:
             amax = ai
             idx = iINDEX0
     return np.intp(idx)

diff --git a/bottleneck/src/template/func/nanargmin.py b/bottleneck/src/template/func/nanargmin.py
@@ -98,7 +98,7 @@ def NAME_NDIMd_DTYPE_axisAXIS(np.ndarray[np.DTYPE_t, ndim=NDIM] a):
     amin = MAXDTYPE
     for iINDEX0 in range(nINDEX0):
         ai = a[INDEXALL]
-        if ai <= amin:
+        if ai < amin:
             amin = ai
             idx = iINDEX0
     return np.intp(idx)

diff --git a/bottleneck/tests/func_test.py b/bottleneck/tests/func_test.py
@@ -27,6 +27,8 @@ def arrays(dtypes=bn.dtypes, nans=True):
                 a = a.reshape(shape)
                 yield a
                 yield -a
+                # nanargmax/nanargmin regression tests
+                yield np.zeros_like(a)
             if issubclass(a.dtype.type, np.inexact):
                 if nans:
                     for i in range(a.size):