fitting scatter plot with two-dimensional normal distribution (Gaussian)?
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buthayna alnaalwa
le 28 Fév 2019
Réponse apportée : buthayna alnaalwa
le 5 Mar 2019
Hi everyone,
I need to fit the attached scatter plot to 2-D normal distribution (Gaussian), as i undertood the expected result should be like ellipsoid, i tried so many think but i could reach what i want! e.g: when i tried the gaussian fit i got like straight line crossing y axis at zero...
this photo generated from x,y of 566*2 matrix.
thanks in advance
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Jeff Miller
le 28 Fév 2019
You can calculate the 5 parameters of the best estimated bivariate normal directly from the x and y values: mean & sd of each variable and Pearson correlation. What else do you want?
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buthayna alnaalwa
le 1 Mar 2019
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Jeff Miller
le 1 Mar 2019
MATLAB has nice functions to calculate the parameter, such as:
% Assume your data are in x,y
muX = mean(x);
sigmaY = std(y);
rhoXY = corr(x,y);
I don't really understand what you want, but your comments about ellipsoids suggest that you are trying to plot the bivariate distribution. The usual way to do that is with a surface plot. Here is a good example from Image Analyst: Previous Answer
You can use your mu & sigma values, computed as above, and adjust xl and yl to give ranges appropriate for the ranges of your x and y
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