how to plot cumulative normal distribution of matlab

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.

Answer 1

[Bjorn Gustavsson]

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]

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]

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