MATLAB Answers

## How to retrieve probabilities from normplot applied to data in matlab?

Asked by MatlabFan

### MatlabFan (view profile)

on 8 Jun 2013
Accepted Answer by Tom Lane

### Tom Lane (view profile)

Hi all,

I have some data to which I've applied the function normplot to see whether or not the distribution is normal. How can I have output the probabilities of the line and data in the normplot ?

Thank you.

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## 1 Answer

### Tom Lane (view profile)

Answer by Tom Lane

### Tom Lane (view profile)

on 9 Jun 2013
Accepted Answer

If you turn on the data cursor in the figure and then click on a point, these values are shown for that point.

If you want to reproduce the calculations, here's one way to do it. This "pop" variable is already sorted; you would need to sort your data to reproduce this.

```load census
normplot(pop)
n = length(pop);
p = ((1:n)'-.5)/n;
popn = mean(pop) + std(pop) * norminv(p);
dataset(p,pop,popn)
```

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