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cdtools/CDTools/tools/initializers.py
T

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Python

from __future__ import division, print_function, absolute_import
import numpy as np
import torch as t
all = ['gaussian']
def gaussian(shape, amplitude, sigma, center = None):
"""Returns an array with a centered gaussian
Takes in the shape, amplitude, and standard deviation of a gaussian
and returns an array with values corresponding to a two-dimensional gaussian function
z = amplitude*exp(-(x-center[0])**2/sigma[0]**2+(y-center[1])**2/sigma[1]**2)
Note that [0, 0] is taken to be at the upper left corner of the array.
Default is centered at ((shape[0]-1)/2, (shape[1]-1)/2)) because x and y are zero-indexed.
Args:
shape (array_like) : A 1x2 array-like object specifying the dimensions of the output array in the form (y shape, x shape)
amplitude (float or int): The amplitude the gaussian to simulate
sigma (array_like): A 1x2 array-like object specifying the x- and y- standard deviation of the gaussian in the form (y stdev, y stdev)
center (array_like) : Optional 1x2 array-like object specifying the location of the center of the gaussian (y center, x center)
Returns:
numpy.array : The real-valued gaussian array
"""
if center is None:
center = ((shape[0]-1)/2, (shape[1]-1)/2)
y, x = np.mgrid[:shape[0], :shape[1]]
return amplitude*np.exp(-((x-center[1])/sigma[1])**2-((y-center[0])/sigma[0])**2)