Add, subtract or multiply two kernels.
kernel : astropy.convolution.kernel
Kernel instance
values : kernel, float or int
Value to operate with
operation : str
One of the following operations: ‘add’ Add two kernels ‘sub’ Subtract two kernels ‘mul’ Multiply kernel with number or convolve two kernels.
Add two kernels
Subtract two kernels
Multiply kernel with number or convolve two kernels.