Standard deviation for Gaussian kernel. The standard deviations of the Gaussian filter are given for each axis as a sequence, or as a single number, in which case it is equal for all axes. Show
The order of the filter along each axis is given as a sequence of integers, or as a single number. An order of 0 corresponds to convolution with a Gaussian kernel. A positive order corresponds to convolution with that derivative of a Gaussian. outputarray or dtype, optionalThe array in which to place the output, or the dtype of the returned array. By default an array of the same dtype as input will be created. modestr or sequence, optionalThe mode parameter determines how the input array is extended when the filter overlaps a border. By passing a sequence of modes with length equal to the number of dimensions of the input array, different modes can be specified along each axis. Default value is ‘reflect’. The valid values and their behavior is as follows: ‘reflect’ (d c b a | a b c d | d c b a)The input is extended by reflecting about the edge of the last pixel. This mode is also sometimes referred to as half-sample symmetric. ‘constant’ (k k k k | a b c d | k k k k)The input is extended by filling all values beyond the edge with the same constant value, defined by the cval parameter. ‘nearest’ (a a a a | a b c d | d d d d)The input is extended by replicating the last pixel. ‘mirror’ (d c b | a b c d | c b a)The input is extended by reflecting about the center of the last pixel. This mode is also sometimes referred to as whole-sample symmetric. ‘wrap’ (a b c d | a b c d | a b c d)The input is extended by wrapping around to the opposite edge. For consistency with the interpolation functions, the following mode names can also be used: ‘grid-constant’This is a synonym for ‘constant’. ‘grid-mirror’This is a synonym for ‘reflect’. ‘grid-wrap’This is a synonym for ‘wrap’. cvalscalar, optionalValue to fill past edges of input if mode is ‘constant’. Default is 0.0. truncatefloat, optionalTruncate the filter at this many standard deviations. Default is 4.0. radiusNone or int or sequence of ints, optionalRadius of the Gaussian kernel. The radius are given for each axis as a sequence, or as a single number, in which case it is equal for all axes. If specified, the size of the kernel along each axis will be Returned array of same shape as input. Notes The multidimensional filter is implemented as a sequence of 1-D convolution filters. The intermediate arrays are stored in the same data type as the output. Therefore, for output types with a limited precision, the results may be imprecise because intermediate results may be stored with insufficient precision. Aly Shmahell Follow Aug 25, 2019 · 4 min read Save A Tutorial on Generating & Plotting 3D Gaussian Distributions with (Python/Numpy/Tensorflow/Pytorch) & (Matplotlib/Plotly). Problem Statement:Whenever plotting Gaussian Distributions is mentioned, it is usually in regard to the Univariate Normal, and that is basically a 2D Gaussian Distribution method that samples from a range array over the X-axis, then applies the Gaussian function to it, and produces the Y-axis coordinates for the plot. In the case of a 3D Gaussian Distribution however, the sampling happens over both the X-axis and the Y-axis, and the coordinates are projected over the Z-axis. This case is rarely mentioned in tutorials, although it is very useful in many situations. Solution Outline:To sample over two axes: X and Y, you need to sample all of the Y-Axis for each sample over the X-axis. The complete sampling over both axes will produce ranges, one over the X-axis and one over the Y-axis. When done, you need to generate a domain over the Z-axis, this can be done by calculating the distances of the (X, Y) samples. The Z domain can then be run through the Gaussian function to produce the Gaussian range over the Z-axis. A 3D plotter then can be constructed to utilize all three ranges to produce a 3D surface. Mathematical Breakdown:
Bivariate Normal (Gaussian) Distribution Generator made with Pure Python
Bivariate Normal (Gaussian) Distribution Generator made with Numpy
Bivariate Normal (Gaussian) Distribution Generator made with Tensorflow
Bivariate Normal (Gaussian) Distribution Generator made with PyTorch
Bivariate Normal Plotter with MatplotlibBivariate Normal Plotter with Plotly (Version 4.0.0)Plotting the Python generated bivariate normal distribution with Matplotlibplt_plot_bivariate_normal_pdf(*py_bivariate_normal_pdf(6, 4, .25)) Plotting the Numpy generated bivariate normal distribution with Matplotlibplt_plot_bivariate_normal_pdf(*np_bivariate_normal_pdf(6, 4, .25)) Plotting the Tensorflow generated bivariate normal distribution with Matplotlibplt_plot_bivariate_normal_pdf(*tf_bivariate_normal_pdf(6, 4, .25)) Plotting the PyTorch generated bivariate normal distribution with Matplotlibplt_plot_bivariate_normal_pdf(*torch_bivariate_normal_pdf(6, 4, .25)) Plotting the Python generated bivariate normal distribution with Plotlyplotly_plot_bivariate_normal_pdf(*py_bivariate_normal_pdf(6, 4, .25)) Plotting the Numpy generated bivariate normal distribution with Plotlyplotly_plot_bivariate_normal_pdf(*np_bivariate_normal_pdf(6, 4, .25)) Plotting the Tensorflow generated bivariate normal distribution with Plotlyplotly_plot_bivariate_normal_pdf(*tf_bivariate_normal_pdf(6, 4, .25)) Plotting the PyTorch generated bivariate normal distribution with Plotlyplotly_plot_bivariate_normal_pdf(*torch_bivariate_normal_pdf(6, 4, .25)) Note to the reader:Please feel free to provide feedback, the reason behind these tutorials afterall is to exchange knowledge, and correct course in case of errors. |