add_array

astropy.nddata.utils.add_array(array_large, array_small, position)

Add a smaller array at a given position in a larger array.

Parameters

array_largendarray

Large array.

array_smallndarray

Small array to add. Can be equal to array_large in size in a given dimension, but not larger.

positiontuple

Position of the small array’s center, with respect to the large array. Coordinates should be in the same order as the array shape.

Returns

new_arrayndarray

The new array formed from the sum of array_large and array_small.

Notes

The addition is done in-place.

Examples

We consider a large array of zeros with the shape 5x5 and a small array of ones with a shape of 3x3:

>>> import numpy as np
>>> from astropy.nddata.utils import add_array
>>> large_array = np.zeros((5, 5))
>>> small_array = np.ones((3, 3))
>>> add_array(large_array, small_array, (1, 2))  
array([[0., 1., 1., 1., 0.],
       [0., 1., 1., 1., 0.],
       [0., 1., 1., 1., 0.],
       [0., 0., 0., 0., 0.],
       [0., 0., 0., 0., 0.]])