scipy.signal.correlate

scipy.signal.correlate(in1, in2, mode='full')

Cross-correlate two N-dimensional arrays.

Cross-correlate in1 and in2 with the output size determined by the mode argument.

Parameters :

in1: array :

first input.

in2: array :

second input. Should have the same number of dimensions as in1.

mode: str {‘valid’, ‘same’, ‘full’}, optional :

A string indicating the size of the output:

• ‘valid’: the output consists only of those elements that do not rely on the zero-padding.
• ‘same’: the output is the same size as in1 centered with respect to the ‘full’ output.
• ‘full’: the output is the full discrete linear cross-correlation of the inputs (default).

Returns :

out: array :

an N-dimensional array containing a subset of the discrete linear cross-correlation of in1 with in2.

Notes

The correlation z of two arrays x and y of rank d is defined as:

z[...,k,...] = sum[..., i_l, ...]
      x[..., i_l,...] * conj(y[..., i_l + k,...])