ptypy.utils.math_utils.delxf

ptypy.utils.math_utils.delxf(a, axis=-1, out=None)

Forward first order derivative for finite difference calculation.

Note

The last element along the derivative direction is set to 0.

Pixel units are used (\(\Delta x = \Delta h = 1\)).

Parameters:

• a (ndarray) – Input array.

• axis (int, Default=-1, optional) – Which direction used for the derivative.

• out (ndarray, Default=None, optional) – Array in wich the resault is written (same size as a).

Returns:

out – Derived array.

Return type:

ndarray