public static ndarray ediff1d(ndarray ary, ndarray to_end = null, ndarray to_begin = null)
{
/*
* The differences between consecutive elements of an array.
*
* Parameters
* ----------
* ary : array_like
* If necessary, will be flattened before the differences are taken.
* to_end : array_like, optional
* Number(s) to append at the end of the returned differences.
* to_begin : array_like, optional
* Number(s) to prepend at the beginning of the returned differences.
*
* Returns
* -------
* ediff1d : ndarray
* The differences. Loosely, this is ``ary.flat[1:] - ary.flat[:-1]``.
*
* See Also
* --------
* diff, gradient
*
* Notes
* -----
* When applied to masked arrays, this function drops the mask information
* if the `to_begin` and/or `to_end` parameters are used.
*
* Examples
* --------
* >>> x = np.array([1, 2, 4, 7, 0])
* >>> np.ediff1d(x)
* array([ 1, 2, 3, -7])
*
* >>> np.ediff1d(x, to_begin=-99, to_end=np.array([88, 99]))
* array([-99, 1, 2, 3, -7, 88, 99])
*
* The returned array is always 1D.
*
* >>> y = [[1, 2, 4], [1, 6, 24]]
* >>> np.ediff1d(y)
* array([ 1, 2, -3, 5, 18])
*/
// force a 1d array
ary = np.asanyarray(ary).ravel();
// fast track default case
if (to_begin is null && to_end is null)
{
return(ary.A("1:") - ary.A(":-1"));
}
int l_begin = 0;
int l_end = 0;
if (to_begin is null)
{
l_begin = 0;
}
else
{
to_begin = np.asanyarray(to_begin).ravel();
l_begin = len(to_begin);
}
if (to_end == null)
{
l_end = 0;
}
else
{
to_end = np.asanyarray(to_end).ravel();
l_end = len(to_end);
}
// do the calculation in place and copy to_begin and to_end
int l_diff = Math.Max(len(ary) - 1, 0);
ndarray result = np.empty(new shape(l_diff + l_begin + l_end), dtype: ary.Dtype);
result = ary.__array_wrap__(result);
if (l_begin > 0)
{
result[":" + l_begin.ToString()] = to_begin;
}
if (l_end > 0)
{
result[(l_begin + l_diff).ToString() + ":"] = to_end;
}
ndarray _out = result.A(l_begin.ToString() + ":" + (l_begin + l_diff).ToString());
_out = np.subtract(ary.A("1:"), ary.A(":-1"));
result[l_begin.ToString() + ":" + (l_begin + l_diff).ToString()] = _out;
return(result);
}