nums.numpy.sqrt

nums.numpy.sqrt(x, out=None, where=True, **kwargs)

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

This docstring was copied from numpy.sqrt.

Some inconsistencies with the NumS version may exist.

Parameters

• x (BlockArray) – The values whose square-roots are required.

• out (BlockArray, None, or 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.

• where (BlockArray, 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, the out array will retain its original value. Note that if an uninitialized out array is created via the default out=None, locations within it where the condition is False will remain uninitialized.

• **kwargs – For other keyword-only arguments, see the ufunc docs.

Returns

y – An array of the same shape as x, containing the positive square-root of each element in x. If any element in x is complex, a complex array is returned (and the square-roots 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.

Return type

BlockArray

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

The doctests shown below are copied from NumPy. They won’t show the correct result until you operate get().

>>> nps.sqrt(nps.array([1,4,9])).get()  
array([ 1.,  2.,  3.])

>>> nps.sqrt(nps.array([4, -1, -3+4J])).get()  
array([ 2.+0.j,  0.+1.j,  1.+2.j])

>>> nps.sqrt(nps.array([4, -1, nps.inf])).get()  
array([ 2., nan, inf])