BUG: isposinf and isneginf now also work with complex values

1 files changed, 17 insertions, 2 deletions

diff --git a/numpy/lib/ufunclike.py b/numpy/lib/ufunclike.py
index e0bd95182..fc059d2f7 100644
--- a/numpy/lib/ufunclike.py
+++ b/numpy/lib/ufunclike.py
@@ -81,6 +81,21 @@ def fix(x, out=None):
         res = res[()]
     return res
 
+
+def _isinf(x, sign, out=None):
+    if nx.isscalar(x):
+        if out is not None:
+            raise ValueError('out has to be None if x is scalar.')
+        return nx.isinf(x) and nx.sign(x) == sign
+    else:
+        x = nx.asanyarray(x)
+        out = nx.isinf(x, out)
+        if x.ndim == 0:
+            out = nx.asanyarray(out)
+        out_b = out.astype(bool, copy=False)
+        out[out_b] = nx.sign(x[out_b]) == sign
+        return out
+
 @_deprecate_out_named_y
 def isposinf(x, out=None):
     """
@@ -138,7 +153,7 @@ def isposinf(x, out=None):
     array([0, 0, 1])
 
     """
-    return nx.logical_and(nx.isinf(x), ~nx.signbit(x), out)
+    return _isinf(x, 1, out=out)
 
 
 @_deprecate_out_named_y
@@ -199,4 +214,4 @@ def isneginf(x, out=None):
     array([1, 0, 0])
 
     """
-    return nx.logical_and(nx.isinf(x), nx.signbit(x), out)
+    return _isinf(x, -1, out=out)