ENH: make spacing available as a ufunc.

5 files changed, 56 insertions, 11 deletions

diff --git a/numpy/core/code_generators/generate_umath.py b/numpy/core/code_generators/generate_umath.py
index 49f2f23d6..c2f1450f7 100644
--- a/numpy/core/code_generators/generate_umath.py
+++ b/numpy/core/code_generators/generate_umath.py
@@ -665,6 +665,11 @@ defdict = {
           docstrings.get('numpy.core.umath.nextafter'),
           TD(flts),
           ),
+'spacing' :
+    Ufunc(1, 1, None,
+          docstrings.get('numpy.core.umath.spacing'),
+          TD(flts),
+          ),
 'modf' :
     Ufunc(1, 2, None,
           docstrings.get('numpy.core.umath.modf'),
diff --git a/numpy/core/code_generators/ufunc_docstrings.py b/numpy/core/code_generators/ufunc_docstrings.py
index 7ccf3f5e8..9b4501469 100644
--- a/numpy/core/code_generators/ufunc_docstrings.py
+++ b/numpy/core/code_generators/ufunc_docstrings.py
@@ -2811,6 +2811,34 @@ add_newdoc('numpy.core.umath', 'nextafter',
     True
     """)
 
+add_newdoc('numpy.core.umath', 'spacing',
+    """
+    Return the distance between x and the nearest adjacent number.
+
+    Parameters
+    ----------
+    x1: array_like
+        Values to find the spacing of.
+
+    Returns
+    -------
+    out : array_like
+        The spacing of values of `x1`.
+
+    Examples
+    --------
+    >>> np.spacing(1, 2) == np.finfo(np.float64).eps
+    True
+
+    Note
+    ----
+    It can be considered as a generalization of EPS: spacing(np.float64(1)) ==
+    np.finfo(np.float64).eps, and there should not be any representable number
+    between x + spacing(x) and x for any finite x.
+
+    spacing of +- inf and nan is nan.
+    """)
+
 add_newdoc('numpy.core.umath', 'sin',
     """
     Trigonometric sine, element-wise.
diff --git a/numpy/core/src/umath/loops.c.src b/numpy/core/src/umath/loops.c.src
index 74404aa99..6efd30c0c 100644
--- a/numpy/core/src/umath/loops.c.src
+++ b/numpy/core/src/umath/loops.c.src
@@ -1096,6 +1096,15 @@ NPY_NO_EXPORT void
 /**end repeat1**/
 
 NPY_NO_EXPORT void
+@TYPE@_spacing(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func))
+{
+    UNARY_LOOP {
+        const @type@ in1 = *(@type@ *)ip1;
+        *((@type@ *)op1) = npy_spacing@c@(in1);
+    }
+}
+
+NPY_NO_EXPORT void
 @TYPE@_copysign(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func))
 {
     BINARY_LOOP {
diff --git a/numpy/core/src/umath/loops.h b/numpy/core/src/umath/loops.h
index 0cf88303d..48aa7ff5b 100644
--- a/numpy/core/src/umath/loops.h
+++ b/numpy/core/src/umath/loops.h
@@ -1611,6 +1611,10 @@ FLOAT_copysign(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func
 NPY_NO_EXPORT void
 FLOAT_nextafter(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
+#line 210
+NPY_NO_EXPORT void
+FLOAT_spacing(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
+
 
 #line 218
 NPY_NO_EXPORT void
@@ -1760,6 +1764,10 @@ DOUBLE_copysign(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(fun
 NPY_NO_EXPORT void
 DOUBLE_nextafter(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
+#line 210
+NPY_NO_EXPORT void
+DOUBLE_spacing(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
+
 
 #line 218
 NPY_NO_EXPORT void
@@ -1909,6 +1917,10 @@ LONGDOUBLE_copysign(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED
 NPY_NO_EXPORT void
 LONGDOUBLE_nextafter(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
+#line 210
+NPY_NO_EXPORT void
+LONGDOUBLE_spacing(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
+
 
 #line 218
 NPY_NO_EXPORT void
@@ -2080,9 +2092,6 @@ NPY_NO_EXPORT void
 CFLOAT_absolute(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
 NPY_NO_EXPORT void
-CFLOAT__arg(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
-
-NPY_NO_EXPORT void
 CFLOAT_sign(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
 #line 372
@@ -2196,9 +2205,6 @@ NPY_NO_EXPORT void
 CDOUBLE_absolute(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
 NPY_NO_EXPORT void
-CDOUBLE__arg(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
-
-NPY_NO_EXPORT void
 CDOUBLE_sign(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
 #line 372
@@ -2312,9 +2318,6 @@ NPY_NO_EXPORT void
 CLONGDOUBLE_absolute(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
 NPY_NO_EXPORT void
-CLONGDOUBLE__arg(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
-
-NPY_NO_EXPORT void
 CLONGDOUBLE_sign(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
 #line 372
diff --git a/numpy/core/src/umath/loops.h.src b/numpy/core/src/umath/loops.h.src
index f99c99cfd..3fc8ecbf6 100644
--- a/numpy/core/src/umath/loops.h.src
+++ b/numpy/core/src/umath/loops.h.src
@@ -204,8 +204,8 @@ NPY_NO_EXPORT void
 @TYPE@_logical_not(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));
 
 /**begin repeat1
- * #kind = isnan, isinf, isfinite, signbit, copysign, nextafter#
- * #func = npy_isnan, npy_isinf, npy_isfinite, npy_signbit, npy_copysign, nextafter#
+ * #kind = isnan, isinf, isfinite, signbit, copysign, nextafter, spacing#
+ * #func = npy_isnan, npy_isinf, npy_isfinite, npy_signbit, npy_copysign, nextafter, spacing#
  **/
 NPY_NO_EXPORT void
 @TYPE@_@kind@(char **args, intp *dimensions, intp *steps, void *NPY_UNUSED(func));