convolution

Small value artifacts from applying scipy.signal.convolve Question: This Python 3.11.5 script: import numpy as np from skimage.io import imread from scipy.signal import convolve image = np.flipud(imread(‘conv-test.bmp’).astype(np.float32)) con = convolve(image, np.ones((3, 3))/9, mode=’valid’) print(image.min()) print(np.logical_and(image > 0, image < 1).any()) print(np.logical_and(con > 0, con < 0.00001).any()) produces: 0.0 False True How is it possible to get …

How to get a convolution of 3 or more continuous PDFs to obtain the average of the PDFs in Python and or R Question: Say I have three random variables. I would like to do a convolution to obtain the average. How do I do this in Python and or R? Edit 1 Also. It …

Convolution of a Gaussian with an asymmetrical Gaussian Question: I’m looking to convolve a Gaussian with an asymmetric Gaussian. My attempt at this is below. import numpy as np import matplotlib.pyplot as plt x=np.linspace(0,5,500) dx=x[1]-x[0] # Gaussian sigma1=0.1 peak1=1 gauss1=np.exp(-(x-peak1)**2/(2*sigma1**2)) # Asymmetric Gaussian gauss2=0.5*np.exp(-(x-1.5)**2/(-0.2+x*0.4)**2) # convolution conv=np.convolve(gauss1,gauss2,mode=’same’)*dx plt.plot(x,gauss1,label=’Gaussian’) plt.plot(x,gauss2,label=’Asymmetric Gaussian’) plt.plot(x,conv,label=’Convolution’) plt.xlim(0,5) plt.legend() plt.show() I …

How to convolution integration(Duhamel Integration) by python? Question: Hi~ I’m studying about structural dynamics. I want to make a code about Duhamel Integration which is kind of Convoution Integration. If the initial conditions are y(0)=0 and y'(0)=0, Duhamel Integration is like this. enter image description here Using Ti Nspire I solved this problem with my …

1D Convolution of 2D arrays Question: I have 2 arrays of sets of signals, both 16×90000 arrays. In other words, 2 arrays with 16 signals in each. I want to perform matched filtering on the signals, row by row, correlating row 1 of array 1 with row 1 of array 2, and so forth. I’ve …

Fourier transform of 2D Gaussian kernel is not matching up with its counterpart in the spatial domain Question: We know the Fourier transform of a Gaussian filter is again Gaussian in the frequency domain, I have written the following method to build a Gaussian kernel: def get_gaussian(size, sigma): g_kernel = np.zeros((size,size)) x_center = size // …

Rolling sum of dataframe column with custom function gets really slow on large averaging windows. Can I fix with convolve? Question: I am using the following function to estimate the Gaussian window rolling average of my timeseries. Though it works great from small size averaging windows, it crushes (or gets extremely slow) for larger averaging …

What happens in a convolution when the stride is larger than the kernel? Question: I recently was experiment with convolutions and transposed convolutions in Pytorch. I noticed with the nn.ConvTranspose2d API (I haven’t tried with the normal convolution API yet), you can specify a stride that is larger than the kernel size and the convolution …

Is there a function in Python similar to Matlab's deconvblind? Question: I’m working on blind deconvoltuion. In iterating L2norm reguralization, I want to update the PSF at the same time, and when I looked it up, I found a function called deconvblind in Matlab: l[J,PSF] = deconvblind(I,INITPSF) deconvolves image I using the maximum likelihood algorithm, …

Why does nn.Conv1d work on 2d feature [b, c, h, w]? Question: I am wondering why conv1d works on 2d feature(batch, channel, height, width). An nn.Conv1d(channel, channel, kernel_size=(1,1)) works when I put 2d feature, but gives different result from nn.Conv2d(channel, channel, kernel_size=1). I want to know why conv1d works and what it mean by 2d …