numpy.sqrt¶

numpy.
sqrt
(x[, out]) = <ufunc 'sqrt'>¶ Return the positive squareroot of an array, elementwise.
Parameters: x : array_like
The values whose squareroots are required.
out : ndarray, optional
Alternate array object in which to put the result; if provided, it must have the same shape as x
Returns: y : ndarray
An array of the same shape as x, containing the positive squareroot of each element in x. If any element in x is complex, a complex array is returned (and the squareroots of negative reals are calculated). If all of the elements in x are real, so is y, with negative elements returning
nan
. If out was provided, y is a reference to it.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, numpy.inf]) array([ 2., NaN, Inf])