ENH: datetime-ufunc: Add m8 / m8 -> f8 case to the datetime ufunc operations

6 files changed, 65 insertions, 15 deletions

diff --git a/numpy/core/code_generators/generate_umath.py b/numpy/core/code_generators/generate_umath.py
index 599ffddc8..957607f40 100644
--- a/numpy/core/code_generators/generate_umath.py
+++ b/numpy/core/code_generators/generate_umath.py
@@ -275,6 +275,7 @@ defdict = {
           TD(intfltcmplx),
           [TypeDescription('m', FullTypeDescr, 'mq', 'm'),
            TypeDescription('m', FullTypeDescr, 'md', 'm'),
+           TypeDescription('m', FullTypeDescr, 'mm', 'd'),
           ],
           TD(O, f='PyNumber_Divide'),
           ),
diff --git a/numpy/core/src/umath/loops.c.src b/numpy/core/src/umath/loops.c.src
index 31345ff45..b23f1018c 100644
--- a/numpy/core/src/umath/loops.c.src
+++ b/numpy/core/src/umath/loops.c.src
@@ -1229,6 +1229,21 @@ TIMEDELTA_md_m_divide(char **args, intp *dimensions, intp *steps, void *NPY_UNUS
     }
 }
 
+NPY_NO_EXPORT void
+TIMEDELTA_mm_d_divide(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func))
+{
+    BINARY_LOOP {
+        const npy_timedelta in1 = *(npy_timedelta *)ip1;
+        const npy_timedelta in2 = *(npy_timedelta *)ip2;
+        if (in1 == NPY_DATETIME_NAT || in2 == NPY_DATETIME_NAT) {
+            *((double *)op1) = NPY_NAN;
+        }
+        else {
+            *((double *)op1) = (double)in1 / (double)in2;
+        }
+    }
+}
+
 /*
  *****************************************************************************
  **                             FLOAT LOOPS                                 **
diff --git a/numpy/core/src/umath/loops.h b/numpy/core/src/umath/loops.h
index 2a827e168..2a792bf5b 100644
--- a/numpy/core/src/umath/loops.h
+++ b/numpy/core/src/umath/loops.h
@@ -2661,6 +2661,9 @@ TIMEDELTA_mq_m_divide(char **args, intp *dimensions, intp *steps, void *NPY_UNUS
 NPY_NO_EXPORT void
 TIMEDELTA_md_m_divide(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
+NPY_NO_EXPORT void
+TIMEDELTA_mm_d_divide(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
+
 /* Special case equivalents to above functions */
 
 #define TIMEDELTA_mq_m_true_divide TIMEDELTA_mq_m_divide
@@ -2678,27 +2681,27 @@ TIMEDELTA_md_m_divide(char **args, intp *dimensions, intp *steps, void *NPY_UNUS
  *****************************************************************************
  */
 
-#line 511
+#line 514
 NPY_NO_EXPORT void
 OBJECT_equal(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
-#line 511
+#line 514
 NPY_NO_EXPORT void
 OBJECT_not_equal(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
-#line 511
+#line 514
 NPY_NO_EXPORT void
 OBJECT_greater(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
-#line 511
+#line 514
 NPY_NO_EXPORT void
 OBJECT_greater_equal(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
-#line 511
+#line 514
 NPY_NO_EXPORT void
 OBJECT_less(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
-#line 511
+#line 514
 NPY_NO_EXPORT void
 OBJECT_less_equal(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
diff --git a/numpy/core/src/umath/loops.h.src b/numpy/core/src/umath/loops.h.src
index bf41e4187..fdedc1933 100644
--- a/numpy/core/src/umath/loops.h.src
+++ b/numpy/core/src/umath/loops.h.src
@@ -487,6 +487,9 @@ TIMEDELTA_mq_m_divide(char **args, intp *dimensions, intp *steps, void *NPY_UNUS
 NPY_NO_EXPORT void
 TIMEDELTA_md_m_divide(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
+NPY_NO_EXPORT void
+TIMEDELTA_mm_d_divide(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
+
 /* Special case equivalents to above functions */
 
 #define TIMEDELTA_mq_m_true_divide TIMEDELTA_mq_m_divide
diff --git a/numpy/core/src/umath/ufunc_object.c b/numpy/core/src/umath/ufunc_object.c
index 2e46fc51a..dcc29f2ba 100644
--- a/numpy/core/src/umath/ufunc_object.c
+++ b/numpy/core/src/umath/ufunc_object.c
@@ -2822,8 +2822,9 @@ type_reso_error: {
 /*
  * This function applies the type resolution rules for division.
  * In particular, there are a number of special cases with datetime:
- *    m8[<A>] / int## => m8[<A>] / int64
- *    m8[<A>] / float## => m8[<A>] / float64
+ *    m8[<A>] / m8[<B>] to  m8[gcd(<A>,<B>)] / m8[gcd(<A>,<B>)]  -> float64
+ *    m8[<A>] / int##   to m8[<A>] / int64 -> m8[<A>]
+ *    m8[<A>] / float## to m8[<A>] / float64 -> m8[<A>]
  */
 NPY_NO_EXPORT int
 PyUFunc_DivisionTypeResolution(PyUFuncObject *ufunc,
@@ -2851,13 +2852,34 @@ PyUFunc_DivisionTypeResolution(PyUFuncObject *ufunc,
     }
 
     if (type_num1 == NPY_TIMEDELTA) {
+        /*
+         * m8[<A>] / m8[<B>] to
+         * m8[gcd(<A>,<B>)] / m8[gcd(<A>,<B>)]  -> float64
+         */
+        if (type_num2 == NPY_TIMEDELTA) {
+            out_dtypes[0] = PyArray_PromoteTypes(PyArray_DESCR(operands[0]),
+                                                PyArray_DESCR(operands[1]));
+            if (out_dtypes[0] == NULL) {
+                return -1;
+            }
+            out_dtypes[1] = out_dtypes[0];
+            Py_INCREF(out_dtypes[1]);
+            out_dtypes[2] = PyArray_DescrFromType(NPY_DOUBLE);
+            if (out_dtypes[2] == NULL) {
+                Py_DECREF(out_dtypes[0]);
+                out_dtypes[0] = NULL;
+                Py_DECREF(out_dtypes[1]);
+                out_dtypes[1] = NULL;
+                return -1;
+            }
+        }
         /* m8[<A>] / int## => m8[<A>] / int64 */
-        if (PyTypeNum_ISINTEGER(type_num2)) {
+        else if (PyTypeNum_ISINTEGER(type_num2)) {
             out_dtypes[0] = ensure_dtype_nbo(PyArray_DESCR(operands[0]));
             if (out_dtypes[0] == NULL) {
                 return -1;
             }
-            out_dtypes[1] = PyArray_DescrNewFromType(NPY_LONGLONG);
+            out_dtypes[1] = PyArray_DescrFromType(NPY_LONGLONG);
             if (out_dtypes[1] == NULL) {
                 Py_DECREF(out_dtypes[0]);
                 out_dtypes[0] = NULL;
diff --git a/numpy/core/tests/test_datetime.py b/numpy/core/tests/test_datetime.py
index b51febb85..c533f3b2c 100644
--- a/numpy/core/tests/test_datetime.py
+++ b/numpy/core/tests/test_datetime.py
@@ -738,31 +738,37 @@ class TestDateTime(TestCase):
             assert_raises(TypeError, np.multiply, 1.5, dta)
 
     def test_datetime_divide(self):
-        for dta, tda, tdb, tdc in \
+        for dta, tda, tdb, tdc, tdd in \
                     [
                      # One-dimensional arrays
                      (np.array(['2012-12-21'], dtype='M8[D]'),
                       np.array([6], dtype='m8[h]'),
                       np.array([9], dtype='m8[h]'),
-                      np.array([12], dtype='m8[h]')),
+                      np.array([12], dtype='m8[h]'),
+                      np.array([6], dtype='m8[m]')),
                      # NumPy scalars
                      (np.datetime64('2012-12-21', '[D]'),
                       np.timedelta64(6, '[h]'),
                       np.timedelta64(9, '[h]'),
-                      np.timedelta64(12, '[h]'))]:
+                      np.timedelta64(12, '[h]'),
+                      np.timedelta64(6, '[m]'))]:
             # m8 / int
             assert_equal(tdc / 2, tda)
             assert_equal((tdc / 2).dtype, np.dtype('m8[h]'))
             # m8 / float
             assert_equal(tda / 0.5, tdc)
             assert_equal((tda / 0.5).dtype, np.dtype('m8[h]'))
+            # m8 / m8
+            assert_equal(tda / tdb, 6.0 / 9.0)
+            assert_equal(tdb / tda, 9.0 / 6.0)
+            assert_equal((tda / tdb).dtype, np.dtype('f8'))
+            assert_equal(tda / tdd, 60.0)
+            assert_equal(tdd / tda, 1.0 / 60.0)
 
             # int / m8
             assert_raises(TypeError, np.divide, 2, tdb)
             # float / m8
             assert_raises(TypeError, np.divide, 0.5, tdb)
-            # m8 / m8
-            assert_raises(TypeError, np.divide, tda, tdb)
             # m8 / M8
             assert_raises(TypeError, np.divide, dta, tda)
             # M8 / m8