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Bivariate Guassian mixed model on 1D data

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Trisha Kibaya
Trisha Kibaya on 24 Aug 2018
Commented: Trisha Kibaya on 28 Aug 2018
Hi, I am trying to plot a guassian curve on the histogram distribution of my 1D data. This is my code:
data = xlsread('csf.xlsx','ab');
mu1 = mean('data');
sigma1 = std('data');
X = [mvnrnd(mu1,sigma1,1000)];
numComponents=2;
paramEsts = fitgmdist(X,numComponents);
MU=[paramEsts.mu(1);paramEsts.mu(2)];
SIGMA=cat(3,[paramEsts.Sigma(1)],[paramEsts.Sigma(2)]);
PPp=[paramEsts.PComponents(1),paramEsts.PComponents(2)];
gm = gmdistribution(MU,SIGMA,PPp);
dimension = gm.NumVariables
rng(1);
min_val = min(data(:)-100); max_val = max (data(:)+1000);
% min_val = min('data'); max_val = max ('data');
histogram(data, 'Normalization', 'pdf', 'EdgeColor', 'none')
x= min_val:0.01:max_val;
xlim([min_val max_val])
hold on;
xgrid = linspace (50,3000,500)';
n1 = makedist('normal',paramEsts.mu(1),sqrt(paramEsts.Sigma(1)));
n2 = makedist('normal',paramEsts.mu(2),sqrt(paramEsts.Sigma(2)));
p = paramEsts.ComponentProportion;
y = p(1)*pdf(n1,xgrid) + p(2)*pdf(n2,xgrid);
hold on; plot(xgrid,y,'b'); hold off
And this is what I get:
However, I am trying to get something like this:
Please, how do I achieve this?

  2 Comments

the cyclist
the cyclist on 24 Aug 2018
Can you upload either the Excel file or the resulting data variable in a MAT file (using that little paperclip icon)?

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Answers (1)

Image Analyst
Image Analyst on 24 Aug 2018
Try something like the attached demo that fits two Gaussians to data. Adapt as needed (like replace blue dots on plot with white bars or whatever).

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Trisha Kibaya
Trisha Kibaya on 28 Aug 2018
Formulas. This is are the codes I used to plot them: xgrid = linspace (40,1000,112110'); n1 = makedist('normal',paramEsts.mu(1),sqrt(paramEsts.Sigma(1))); n2 = makedist('normal',paramEsts.mu(2),sqrt(paramEsts.Sigma(2))); p = paramEsts.ComponentProportion; y1 = p(1)*pdf(n1,xgrid); hold on; plot (xgrid, y1,'b'); hold off y2 = p(2)*pdf(n2,xgrid); hold on; plot (xgrid, y2,'r'); hold off
Trisha Kibaya
Trisha Kibaya on 28 Aug 2018
Thanks. I am still new at this, I had no idea that I posted my code in the wrong way. Sorry about that.
xgrid = linspace (40,1000,112110');
n1 = makedist('normal',paramEsts.mu(1),sqrt(paramEsts.Sigma(1)));
n2 = makedist('normal',paramEsts.mu(2),sqrt(paramEsts.Sigma(2)));
p = paramEsts.ComponentProportion;
y1 = p(1)*pdf(n1,xgrid); hold on; plot (xgrid, y1,'b'); hold off
y2 = p(2)*pdf(n2,xgrid); hold on; plot (xgrid, y2,'r'); hold off

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