# how to plot cumulative normal distribution of matlab

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Sajid Afaque on 8 Jun 2020
i have a data "z_hist" which i have enclosed below.
now i need to plot cumulative normal distribution which looks something like below image where my x-axis would be range from min(z_hist) to max(z_hist).
how do i plot it.
any help would be appreciated.

Bjorn Gustavsson on 8 Jun 2020
If you have the statistics toolbox you have direct access to the cummulative distribution of a number of pdfs. Try to look at the help and documentation for normcdf, and you will see:
normcdf Normal cumulative distribution function (cdf).
P = normcdf(X,MU,SIGMA) returns the cdf of the normal distribution
If you don't have the statistics toolbox you will have to figure out how to calculate it yourself - which should be very simple since matlab gives you the error-functions. See for example: Normal ditribution.
HTH

Sajid Afaque on 8 Jun 2020
do i need to take mean and standard deviation of my data. i.e z_hist.
once i calculate p,how do i plot is to get above graph
Bjorn Gustavsson on 8 Jun 2020
Before doing anything like that, you first need to take a look at your data. Do something like this:
subplot(2,1,1)
plot(z)
subplot(2,1,2)
hist(z,40)
Then have a think about how your data fits with respect to a normal-distribution and what you might need to do next (check that you have the right data perhaps?).
HTH