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| author | Bhavuk kalra <bhavukkalra1786@gmail.com> | 2022-06-13 21:38:27 +0530 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2022-06-13 09:08:27 -0700 |
| commit | c74cdc87822f62156db3e10e3bb566d54fa41745 (patch) | |
| tree | 2eeb52725c4806e1ca591efa1c36cc78a73dc495 /numpy | |
| parent | c8dd91b633798a4082f255784dec483b08351f58 (diff) | |
| download | numpy-c74cdc87822f62156db3e10e3bb566d54fa41745.tar.gz | |
DOC: update logarithm docs as per theory. (#21587)
Made some changes addressing the discussions in Issue #21235 .
What this PR updates
Range of log functions in the Docs
Adds Additional Notes on the theoretical range outcomes. -pi
Diffstat (limited to 'numpy')
| -rw-r--r-- | numpy/core/code_generators/ufunc_docstrings.py | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/numpy/core/code_generators/ufunc_docstrings.py b/numpy/core/code_generators/ufunc_docstrings.py index 24b707a12..7c020fa2e 100644 --- a/numpy/core/code_generators/ufunc_docstrings.py +++ b/numpy/core/code_generators/ufunc_docstrings.py @@ -2011,7 +2011,7 @@ add_newdoc('numpy.core.umath', 'log', ----- Logarithm is a multivalued function: for each `x` there is an infinite number of `z` such that `exp(z) = x`. The convention is to return the - `z` whose imaginary part lies in `[-pi, pi]`. + `z` whose imaginary part lies in `(-pi, pi]`. For real-valued input data types, `log` always returns real output. For each value that cannot be expressed as a real number or infinity, it @@ -2021,6 +2021,10 @@ add_newdoc('numpy.core.umath', 'log', has a branch cut `[-inf, 0]` and is continuous from above on it. `log` handles the floating-point negative zero as an infinitesimal negative number, conforming to the C99 standard. + + In the cases where the input has a negative real part and a very small + negative complex part (approaching 0), the result is so close to `-pi` + that it evaluates to exactly `-pi`. References ---------- @@ -2061,7 +2065,7 @@ add_newdoc('numpy.core.umath', 'log10', ----- Logarithm is a multivalued function: for each `x` there is an infinite number of `z` such that `10**z = x`. The convention is to return the - `z` whose imaginary part lies in `[-pi, pi]`. + `z` whose imaginary part lies in `(-pi, pi]`. For real-valued input data types, `log10` always returns real output. For each value that cannot be expressed as a real number or infinity, @@ -2072,6 +2076,10 @@ add_newdoc('numpy.core.umath', 'log10', `log10` handles the floating-point negative zero as an infinitesimal negative number, conforming to the C99 standard. + In the cases where the input has a negative real part and a very small + negative complex part (approaching 0), the result is so close to `-pi` + that it evaluates to exactly `-pi`. + References ---------- .. [1] M. Abramowitz and I.A. Stegun, "Handbook of Mathematical Functions", @@ -2112,7 +2120,7 @@ add_newdoc('numpy.core.umath', 'log2', Logarithm is a multivalued function: for each `x` there is an infinite number of `z` such that `2**z = x`. The convention is to return the `z` - whose imaginary part lies in `[-pi, pi]`. + whose imaginary part lies in `(-pi, pi]`. For real-valued input data types, `log2` always returns real output. For each value that cannot be expressed as a real number or infinity, @@ -2123,6 +2131,10 @@ add_newdoc('numpy.core.umath', 'log2', handles the floating-point negative zero as an infinitesimal negative number, conforming to the C99 standard. + In the cases where the input has a negative real part and a very small + negative complex part (approaching 0), the result is so close to `-pi` + that it evaluates to exactly `-pi`. + Examples -------- >>> x = np.array([0, 1, 2, 2**4]) |