numpy.cos

numpy.cos(x[, out]) = <ufunc 'cos'>

Cosine element-wise.

Parameters:

x : array_like

Input array in radians.

out : ndarray, optional

Output array of same shape as x.

Returns:

y : ndarray

The corresponding cosine values.

Raises:

ValueError: invalid return array shape

if out is provided and out.shape != x.shape (See Examples)

Notes

If out is provided, the function writes the result into it, and returns a reference to out. (See Examples)

References

M. Abramowitz and I. A. Stegun, Handbook of Mathematical Functions. New York, NY: Dover, 1972.

Examples

>>> np.cos(np.array([0, np.pi/2, np.pi]))
array([  1.00000000e+00,   6.12303177e-17,  -1.00000000e+00])
>>>
>>> # Example of providing the optional output parameter
>>> out2 = np.cos([0.1], out1)
>>> out2 is out1
True
>>>
>>> # Example of ValueError due to provision of shape mis-matched `out`
>>> np.cos(np.zeros((3,3)),np.zeros((2,2)))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid return array shape
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid return array shape