def ptp(a, axis=None, out=None):
try:<EOL><INDENT>ptp = a.ptp<EOL><DEDENT>except AttributeError:<EOL><INDENT>return _wrapit(a, '<STR_LIT>', axis, out)<EOL><DEDENT>return ptp(axis, out)<EOL>
Range of values (maximum - minimum) along an axis.

The name of the function comes from the acronym for 'peak to peak'.

Parameters
----------
a : array_like
    Input values.
axis : int, optional
    Axis along which to find the peaks.  By default, flatten the
    array.
out : array_like
    Alternative output array in which to place the result. It must
    have the same shape and buffer length as the expected output,
    but the type of the output values will be cast if necessary.

Returns
-------
ptp : ndarray
    A new array holding the result, unless `out` was
    specified, in which case a reference to `out` is returned.

Examples
--------
>>> x = np.arange(4).reshape((2,2))
>>> x
array([[0, 1],
       [2, 3]])

>>> np.ptp(x, axis=0)
array([2, 2])

>>> np.ptp(x, axis=1)
array([1, 1])