MATLAB: 95% area under data set

curve fit

Hello,

I have a set of data representing current as a function of angles as shown in the attached figure. The data sets I have are not Gaussian and I would like to find the 95% area under the curve along with the x1 and x2 position to add to the plot, but I do not have the stat or curve fit toolbox. How can I do this in Matlab?

Thanks

Best Answer

Without your data, I can only outline the approach I would use. First, use the cumtrapz function to do the integration. Normalise the area to 1 by dividing the result of your cumtrapz call by the last value of the vector. Then use the interp1 function to calculate the value of the 2.5% and 97.5% values. Those will be the limits of the central 95%.

Related Solutions

MATLAB: What is the interpretation of trapz(x,cumtrapz(x,y))

It would effectively be a double integration over the same domain

MATLAB: How to shade area of Integral

I’m not quite certain what you want. This shades the area between the x-axis and the value of the integral over the interval (0,5):

y = @(z) -1*z.^3+4*z.^2+-5*z+2;
x = linspace(0, 5);
inty = cumtrapz(x,y(x));
figure(1)
plot(x, inty, '-k', 'LineWidth',1)
hold on
patch([x fliplr(x)], [zeros(size(x)) fliplr(inty)], 'g')
hold off
grid

Best Answer

Related Solutions

MATLAB: What is the interpretation of trapz(x,cumtrapz(x,y))

MATLAB: How to shade area of Integral

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