numpy.random.randn |
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Return a sample (or samples) from the “standard normal” distribution. Note This is a convenience function for users porting code from Matlab, and wraps standard_normal. That function takes a tuple to specify the size of the output, which is consistent with other NumPy functions like numpy.zeros and numpy.ones. Note New code should use the standard_normal method of a Generator instance instead; please see the Quick Start. If positive int_like arguments are provided, randn generates an array of shape (d0, d1, ..., dn), filled with random floats sampled from a univariate “normal” (Gaussian) distribution of mean 0 and variance 1. A single float randomly sampled from the distribution is returned if no argument is provided. Parameters: d0, d1, …, dnint, optionalThe dimensions of the returned array, must be non-negative. If no argument is given a single Python float is returned. Returns: Zndarray or floatA (d0, d1, ..., dn)-shaped array of floating-point samples from the standard normal distribution, or a single such float if no parameters were supplied. See also standard_normalSimilar, but takes a tuple as its argument. normalAlso accepts mu and sigma arguments. random.Generator.standard_normalwhich should be used for new code. Notes For random samples from the normal distribution with mean mu and standard deviation sigma, use: sigma * np.random.randn(...) + muExamples >>> np.random.randn() 2.1923875335537315 # randomTwo-by-four array of samples from the normal distribution with mean 3 and standard deviation 2.5: >>> 3 + 2.5 * np.random.randn(2, 4) array([[-4.49401501, 4.00950034, -1.81814867, 7.29718677], # random [ 0.39924804, 4.68456316, 4.99394529, 4.84057254]]) # random |
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