topic Re: Normal Probability Plot with group of data in Discussions

Normal Probability Plot with group of data

MomentHorse550 — Thu, 12 Mar 2026 15:40:15 GMT

Hi everyone,

I would like to reproduce the type of plot shown in the attached figure.
The graph displays multiple datasets overlaid on a Normal Probability (Probit) scale on the Y‑axis, with each group shown using different marker colors and shapes.

Could you please advise which JMP platform(s) and workflow are best suited to generate such a graph?

More specifically, I would like to know:

Which JMP platform to use (e.g., Graph Builder, Distribution, Fit Y by X, or Probability Plot)
How to set the Y‑axis to Normal Probit (σ units)
How to overlay multiple groups on the same probability plot
How to customize markers and colors for each group
How to add a legend similar to the one in the example
Whether the underlying data table needs to be in long format (Value, Group) or wide format

Any example, instructions, or JSL script would be extremely helpful.

Thanks a lot in advance!

Re: Normal Probability Plot with group of data

Mark_Bailey — Tue, 17 Mar 2026 12:09:46 GMT

I will use Big Class (JMP Sample Data folder) to illustrate. I assume that all the data is stacked in one column for the Y role. The corresponding group assignments exist in another column.

Select Analyze > Distribution
Select the height data column and click Y
Select the grouping column sex and click By
Click OK

The distribution platform will compute the quantiles and save them for you.

Press and hold the CTRL key with Windows or the Command key with Mac
Click the red triangle for height and select Normal Quantile Plot
Press and hold the CTRL key with Windows or the Command key with Mac
Click the red triangle for height and select Save > Normal Quantiles.

You are ready to plot!

Select Graph > Graph Builder
Drag height to the Y role
Drag normal quantiles to the X role
Drag sex to the Overlay role

These steps should produce the plot you want.

Re: Normal Probability Plot with group of data

hogi — Thu, 12 Mar 2026 17:28:25 GMT

grouped Cumulative Probability in Graph Builder

if you have access to JMP 19, you can try the new Scoping :

- select your variable and in the right click menu pick Distributional: Cumulative Probability
- activate Scoping : Overlay and pick the Overlay column
- use Normal Probability in the axis settings

-> done

Re: Normal Probability Plot with group of data

MomentHorse550 — Thu, 12 Mar 2026 20:38:46 GMT

Thanks Hogi. I have tried that but it does not give [+/-sigma] as unit for the plot.

Re: Normal Probability Plot with group of data

hogi — Thu, 12 Mar 2026 21:30:17 GMT

Oh, I missed this point, then you have to wrap the cumulative probability with normal quantile() - and you don't have to adjust the axis scale.

Normal Quantile(Col Rank( :height, :sex ) / (Col Number( :height, :sex ) + 1))