Questions tagged [gaussian]

For issues related to any of the uses of the Gaussian function. Don't forget to add additional tags to clarify the context.

The graph of a Gaussian is a characteristic symmetric "bell curve" shape that quickly falls off towards plus/minus infinity. The 1-D Gaussian is defined as (taken from wikipedia):

gaussian function from wikipedia

The parameter a is the height of the curve's peak, b is the position of the centre of the peak, and c controls the width of the "bell".

In multiple dimensions, the Gaussian is defined as the product of 1D curves along each dimension.

Gaussian functions are widely used in statistics where they describe the normal distributions, in signal processing where they serve to define Gaussian filters, in image processing where two-dimensional Gaussians are used for Gaussian blurs, in mathematics and physics where they are used to solve heat equations and diffusion equations, to formulate the propagation of optical beams (Gaussian beams), to from a basis set of wavefunctions, to define the Weierstrass transform, and many more.

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Arrays, plotting, fitting gaussian distribution for multiples on graph which represents a power spectrum

This is the code I have done which reads in a data text file which has some metadata at the start. And then 2 columns of data which represent Angle 2 theta on the left column and Radiation count in the right column. My code looks for the value of…
Nirvan
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Gaussian Distribution little help in C

I am trying to generate the Gaussian Distribution using Method 2 and Method 3 described here: http://c-faq.com/lib/gaussian.html The problem is I am little confused as I have sigma and Mean and the 100 numbers with the range of 0 to 1 but in these…
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After fitting a data to Gaussian model, how to check if a new data fall within a variance distance of the model

If we have a data set that we already fit in a 3D Gaussian model. We have now the mean, the covariance matrix and the pdf. If I have a new data point that I wanted to check if it is within the covariance (inside the model). For some reasons, I need…
KaMu
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Expectation maximization in opencv

My problem is this: I have to approximate a distribution with a mixture of two-component Gaussian model. In particular I need to two variances of the two Gaussian distributions. In openCv I can use the class EM; problem is that I can obtain only two…
Alessandro
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Using scipy integrate tplquad to evaluate triple integral of multivariate gaussian

I'm trying to perform the following triple integral: f(v) is a 3 variable Gaussian probability density function. The magnitude of the resultant velocity, V, must be less than some Vmax (so Vx, Vy, and Vz can each range from 0 or -Vmax to +Vmax, but…
user23870
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Gaussian Weighting for point re-distribution

I am working with some points which are very compact together and therefore forming clusters amongst them is proving very difficult. Since I am new to this concept, I read in a paper about the concept of Gaussian weighting the points randomly or…
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Access Violation in CvEM::getCovs function

I am using cvEm for Gaussian Mixture modeling on a 2D data. After calling the train function it returns True (signing a successful training) and also classification results (having different clusters in different colors) seem reasonable, but I get…
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How to maximize the log-likelihood for a Gaussian Process in Mathematica

I am currently trying to implement a Gaussian Process in Mathematica and am stuck with the maximization of the loglikelihood. I just tried to use the FindMaximum formula on my loglikelihood function but this does not seem to work on this function. …
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MATLAB Adding Gaussian fit to histogram

I am trying to add Gaussian fit to the histogram in MATLAB, but I do not know how to apply the fit to one particular peak only. http://postimg.org/image/phms61rdh/ first plot http://postimg.org/image/sindrn8er/ second plot I am also posting part of…
sanpaula
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Matlab Vectorization of Multivariate Gaussian Basis Functions

I have the following code for calculating the result of a linear combination of Gaussian functions. What I'd really like to do is to vectorize this somehow so that it's far more performant in Matlab. Note that y is a column vector (output), x is a…
Mark Jerzykowski
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Adding Poisson noise with a Gaussian distribution

I managed to add poisson noise to my .fits image, but I need to add noise that is distributed like a gaussian with mean/median (mu_0) of 0 and an increasingly wider distribution (sigma). I couldn't find the syntax governing the adding of noise in…
vdogsandman
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Python: 4-curve gaussian fitting with non-linear least-squares with multiple spectra

I'm using the top rated code from here and modified it to fit 4 gaussian gives for 3 spectra. The code works when I'm just doing working one spectra at a time but I want to automate the code so that I do curve fitting on multiple spectra. Here is…
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Draw ellipses on people using Expectation Maximization with OpenCV

I have a few doubts about how to approach my goal. I have an outside camera who is recording people and I want to draw an ellipse on every person. Right now what I do is get the feature points of the people from the frame (I get them using a mask…
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Why am I getting the return value of None and what does it mean?

I do no understand very well, the result: "none". I am trying to start elimination (Gauss) code, but I receive the result: "None". from numpy import * a= array([[1,0],[0,2]]) b= array([1,4]) def gauss(a,b): n=len(b) k=0 while k in…
user2852600
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Creating translucent UIView with gaussian blur

I am in the process of creating an app where I have a background image (a UIImageView with the frame set to the UIView's bounds and added as a subview). I would like to now add a UIView that will be over the background image but will apply gaussian…
Alexander North
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