BUG: core/umath: make complex number comparisons False when *either* element is nan

This also fixes NaN propagation in np.maximum/minimum, for example in
the case for

    maximum(1, complex(0, nan)) -> (0, nan)

which previously yielded (1, 0).

3 files changed, 35 insertions, 8 deletions

diff --git a/numpy/core/src/umath/loops.c.src b/numpy/core/src/umath/loops.c.src
index cef45bdcb..e77da0691 100644
--- a/numpy/core/src/umath/loops.c.src
+++ b/numpy/core/src/umath/loops.c.src
@@ -1299,10 +1299,14 @@ NPY_NO_EXPORT void
  *****************************************************************************
  */
 
-#define CGE(xr,xi,yr,yi) (xr > yr || (xr == yr && xi >= yi))
-#define CLE(xr,xi,yr,yi) (xr < yr || (xr == yr && xi <= yi))
-#define CGT(xr,xi,yr,yi) (xr > yr || (xr == yr && xi > yi))
-#define CLT(xr,xi,yr,yi) (xr < yr || (xr == yr && xi < yi))
+#define CGE(xr,xi,yr,yi) ((xr > yr && !npy_isnan(xi) && !npy_isnan(yi)) \
+                          || (xr == yr && xi >= yi))
+#define CLE(xr,xi,yr,yi) ((xr < yr && !npy_isnan(xi) && !npy_isnan(yi)) \
+                          || (xr == yr && xi <= yi))
+#define CGT(xr,xi,yr,yi) ((xr > yr && !npy_isnan(xi) && !npy_isnan(yi)) \
+                          || (xr == yr && xi > yi))
+#define CLT(xr,xi,yr,yi) ((xr < yr && !npy_isnan(xi) && !npy_isnan(yi)) \
+                          || (xr == yr && xi < yi))
 #define CEQ(xr,xi,yr,yi) (xr == yr && xi == yi)
 #define CNE(xr,xi,yr,yi) (xr != yr || xi != yi)
 
diff --git a/numpy/core/tests/test_regression.py b/numpy/core/tests/test_regression.py
index 01cf5dad4..b676e633c 100644
--- a/numpy/core/tests/test_regression.py
+++ b/numpy/core/tests/test_regression.py
@@ -1338,5 +1338,9 @@ class TestRegression(TestCase):
         assert_(ret is out)
         assert_array_equal(ret, data.std(axis=1))
 
+    def test_complex_nan_maximum(self):
+        cnan = complex(0, np.nan)
+        assert_equal(np.maximum(1, cnan), cnan)
+
 if __name__ == "__main__":
     run_module_suite()
diff --git a/numpy/core/tests/test_umath.py b/numpy/core/tests/test_umath.py
index 6fcb2dcf0..2741287ec 100644
--- a/numpy/core/tests/test_umath.py
+++ b/numpy/core/tests/test_umath.py
@@ -378,7 +378,7 @@ class TestMaximum(TestCase):
 
     def test_complex_nans(self):
         nan = np.nan
-        for cnan in [nan, nan*1j, nan + nan*1j] :
+        for cnan in [complex(nan, 0), complex(0, nan), complex(nan, nan)] :
             arg1 = np.array([0, cnan, cnan], dtype=np.complex)
             arg2 = np.array([cnan, 0, cnan], dtype=np.complex)
             out  = np.array([nan, nan, nan], dtype=np.complex)
@@ -399,7 +399,7 @@ class TestMinimum(TestCase):
 
     def test_complex_nans(self):
         nan = np.nan
-        for cnan in [nan, nan*1j, nan + nan*1j] :
+        for cnan in [complex(nan, 0), complex(0, nan), complex(nan, nan)] :
             arg1 = np.array([0, cnan, cnan], dtype=np.complex)
             arg2 = np.array([cnan, 0, cnan], dtype=np.complex)
             out  = np.array([nan, nan, nan], dtype=np.complex)
@@ -420,7 +420,7 @@ class TestFmax(TestCase):
 
     def test_complex_nans(self):
         nan = np.nan
-        for cnan in [nan, nan*1j, nan + nan*1j] :
+        for cnan in [complex(nan, 0), complex(0, nan), complex(nan, nan)] :
             arg1 = np.array([0, cnan, cnan], dtype=np.complex)
             arg2 = np.array([cnan, 0, cnan], dtype=np.complex)
             out  = np.array([0,    0, nan], dtype=np.complex)
@@ -441,7 +441,7 @@ class TestFmin(TestCase):
 
     def test_complex_nans(self):
         nan = np.nan
-        for cnan in [nan, nan*1j, nan + nan*1j] :
+        for cnan in [complex(nan, 0), complex(0, nan), complex(nan, nan)] :
             arg1 = np.array([0, cnan, cnan], dtype=np.complex)
             arg2 = np.array([cnan, 0, cnan], dtype=np.complex)
             out  = np.array([0,    0, nan], dtype=np.complex)
@@ -1050,5 +1050,24 @@ def test_reduceat():
     assert_array_almost_equal(h1, h2)
         
 
+def test_complex_nan_comparisons():
+    nans = [complex(np.nan, 0), complex(0, np.nan), complex(np.nan, np.nan)]
+    fins = [complex(1, 0), complex(-1, 0), complex(0, 1), complex(0, -1),
+            complex(1, 1), complex(-1, -1), complex(0, 0)]
+
+    for x in nans + fins:
+        x = np.array([x])
+        for y in nans + fins:
+            y = np.array([y])
+
+            if np.isfinite(x) and np.isfinite(y):
+                continue
+
+            assert_equal(x < y, False, err_msg="%r < %r" % (x, y))
+            assert_equal(x > y, False, err_msg="%r > %r" % (x, y))
+            assert_equal(x <= y, False, err_msg="%r <= %r" % (x, y))
+            assert_equal(x >= y, False, err_msg="%r >= %r" % (x, y))
+            assert_equal(x == y, False, err_msg="%r == %r" % (x, y))
+
 if __name__ == "__main__":
     run_module_suite()