numpy.sqrt
-
numpy.sqrt(x, /, out=None, *, where=True, casting='same_kind', order='K', dtype=None, subok=True[, signature, extobj]) = <ufunc 'sqrt'>
-
Return the non-negative square-root of an array, element-wise.
- Parameters
-
-
xarray_like
-
The values whose square-roots are required.
-
outndarray, None, or tuple of ndarray and None, optional
-
A location into which the result is stored. If provided, it must have a shape that the inputs broadcast to. If not provided or None, a freshly-allocated array is returned. A tuple (possible only as a keyword argument) must have length equal to the number of outputs.
-
wherearray_like, optional
-
This condition is broadcast over the input. At locations where the condition is True, the
out
array will be set to the ufunc result. Elsewhere, theout
array will retain its original value. Note that if an uninitializedout
array is created via the defaultout=None
, locations within it where the condition is False will remain uninitialized. - **kwargs
-
For other keyword-only arguments, see the ufunc docs.
-
- Returns
-
-
yndarray
-
An array of the same shape as
x
, containing the positive square-root of each element inx
. If any element inx
is complex, a complex array is returned (and the square-roots of negative reals are calculated). If all of the elements inx
are real, so isy
, with negative elements returningnan
. Ifout
was provided,y
is a reference to it. This is a scalar ifx
is a scalar.
-
See also
-
lib.scimath.sqrt
-
A version which returns complex numbers when given negative reals.
Notes
sqrt has–consistent with common convention–as its branch cut the real “interval” [
-inf
, 0), and is continuous from above on it. A branch cut is a curve in the complex plane across which a given complex function fails to be continuous.Examples
>>> np.sqrt([1,4,9]) array([ 1., 2., 3.])
>>> np.sqrt([4, -1, -3+4J]) array([ 2.+0.j, 0.+1.j, 1.+2.j])
>>> np.sqrt([4, -1, np.inf]) array([ 2., nan, inf])
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Licensed under the 3-clause BSD License.
https://numpy.org/doc/1.19/reference/generated/numpy.sqrt.html