diff options
| author | Muhammad Motawe <muhammad.a.motawe@gmail.com> | 2021-10-30 16:44:37 +0000 |
|---|---|---|
| committer | Muhammad Motawe <muhammad.a.motawe@gmail.com> | 2021-10-30 17:11:28 +0000 |
| commit | fce2a361dad67566a6252553492239ec7b0c916d (patch) | |
| tree | f3fd363c09dbc353e7606d017bd8812b99c89bee | |
| parent | 7c512e05192376ae118f9c2a05faf0fe50673aa4 (diff) | |
| download | numpy-fce2a361dad67566a6252553492239ec7b0c916d.tar.gz | |
DOC: Clarify behavior of np.lib.scimath.sqrt in the presence of negative 0
| -rw-r--r-- | numpy/core/code_generators/ufunc_docstrings.py | 1 | ||||
| -rw-r--r-- | numpy/lib/scimath.py | 14 |
2 files changed, 15 insertions, 0 deletions
diff --git a/numpy/core/code_generators/ufunc_docstrings.py b/numpy/core/code_generators/ufunc_docstrings.py index ab5f74df3..191f4f1cc 100644 --- a/numpy/core/code_generators/ufunc_docstrings.py +++ b/numpy/core/code_generators/ufunc_docstrings.py @@ -3827,6 +3827,7 @@ add_newdoc('numpy.core.umath', 'sqrt', -------- lib.scimath.sqrt A version which returns complex numbers when given negative reals. + Note: 0.0 and -0.0 are handled differently for complex inputs. Notes ----- diff --git a/numpy/lib/scimath.py b/numpy/lib/scimath.py index 308f1328b..afaf4b4c9 100644 --- a/numpy/lib/scimath.py +++ b/numpy/lib/scimath.py @@ -234,6 +234,20 @@ def sqrt(x): >>> np.emath.sqrt([-1,4]) array([0.+1.j, 2.+0.j]) + Different results are expected because: + floating point 0.0 and -0.0 are distinct. + + For more control, explicitly use complex() as follows: + + >>> np.emath.sqrt(complex(-4.0, 0.0)) + 2j + >>> np.emath.sqrt(complex(-4.0, -0.0)) + -2j + + + + + """ x = _fix_real_lt_zero(x) return nx.sqrt(x) |