Difference between np.int, np.int_, int, and np.int_t in cython?

It’s a bit complicated because the names have different meanings depending on the context. int In Python The int is normally just a Python type, it’s of arbitrary precision, meaning that you can store any conceivable integer inside it (as long as you have enough memory). >>> int(10**50) 100000000000000000000000000000000000000000000000000 However, when you use it as …

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Different std in pandas vs numpy

In a nutshell, neither is “incorrect”. Pandas uses the unbiased estimator (N-1 in the denominator), whereas Numpy by default does not. To make them behave the same, pass ddof=1 to numpy.std(). For further discussion, see Can someone explain biased/unbiased population/sample standard deviation? Population variance and sample variance. Why divide by n-1?

How to read an image in Python OpenCV

If you are trying to display OpenCV image using matplotlib, use the code below. import numpy as np import cv2 import matplotlib.pyplot as plt %matplotlib inline # if you are running this code in Jupyter notebook # reads image ‘opencv-logo.png’ as grayscale img = cv2.imread(‘/path_to_image/opencv-logo.png’, 0) plt.imshow(img, cmap=’gray’)

Filtering (reducing) a NumPy Array

Summary Using a loop-based approach with single pass and copying, accelerated with Numba, offers the best overall trade-off in terms of speed, memory efficiency and flexibility. If the execution of the condition function is sufficiently fast, two-passes (filter2_nb()) may be faster, while they are more memory efficient regardless. Also, for sufficiently large inputs, resizing instead …

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Cannot install NumPy from a wheel format

Short answer: rename the file to numpy-1.9.1%2Bmkl-cp34-none-win32.whl to install it. You can check what tags your pip tool accepts for installation by running: import pip; print(pip.pep425tags.get_supported()) In this case pip is incorrectly detecting your operating system to be 32-bits and the file you’re trying to install was win_amd64 in its filename. If you rename the …

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