numpy.sqrt

numpy.sqrt(x[, out])

Return the positive square-root of an array, element-wise.

Parameters:

x : array_like

The square root of each element in this array is calculated.

Returns:

y : ndarray

An array of the same shape as x, containing the square-root of each element in x. If any element in x is complex, a complex array is returned. If all of the elements of x are real, negative elements return numpy.nan elements.

See also

numpy.lib.scimath.sqrt

A version which returns complex numbers when given negative reals.

Notes

sqrt has a branch cut [-inf, 0) and is continuous from above on it.

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])