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jaboraws

Community Trekker

Joined:

Mar 29, 2016

how to convert p value of <.0001 to actual number

Is it possible to get an actual number for pvalues instead of "<.0001"?

1 ACCEPTED SOLUTION

Accepted Solutions
martindemel

Staff

Joined:

Jul 10, 2014

Solution

Re: how to convert p value of <.0001 to actual number

The reason why you see 0e+0 is most likely that the number of leading zeros after the decimal is higher than what you asked to display. Then JMP or any other software can only represent what is given by the calculations which is 0 then.

However, you should be aware of floating point arithmetic and what it is capable of calculating.1e-17 usually is the point where a floating point number cannot differentiate from 0, which means every non-zero value smaller than 1e-17 will be interpreted in calcualtions as zeros. That's (within others) for what symbolic math is good for, because you use symbolic values to deal with that, and the maths behind will calculate further on with mathematical rules rather than actual numeric calculations. Just a side note

14 REPLIES
ms

Super User

Joined:

Jun 23, 2011

Re: how to convert p value of <.0001 to actual number

In report table boxes, double-click on a p-value (or any number col box) to bring up the number format window. Change the setting from "PValue" to "Best".

jaboraws

Community Trekker

Joined:

Mar 29, 2016

Re: how to convert p value of <.0001 to actual number

Thanks but I have already tried that and the "<.0001" values just get converted to "0". 

ron_horne

Super User

Joined:

Jun 23, 2011

Re: how to convert p value of <.0001 to actual number

try changing it to fixed Dec as follows:

12768_pastedImage_0.png

jaboraws

Community Trekker

Joined:

Mar 29, 2016

Re: how to convert p value of <.0001 to actual number

Thanks but I also tried that, even maxing out the width and decimal places and still converts is to simply "0" or "0.00000..........".   

ms

Super User

Joined:

Jun 23, 2011

Re: how to convert p value of <.0001 to actual number

Try to edit the width of the number. But maybe there is a limit for how small numbers JMP will show.

Here's a really small p-value from an ANOVA (I use JMP 12.2).

Prob > F

4,3e-179

jaboraws

Community Trekker

Joined:

Mar 29, 2016

Re: how to convert p value of <.0001 to actual number

Thanks again, I tried that as well and it still just converts it to "0".  Actually the p value you got is exactly what I want as well.  Not sure why I cannot convert it like you.  I also am using JMP12.2. 

Example:

12770_pastedImage_0.png

martindemel

Staff

Joined:

Jul 10, 2014

Re: how to convert p value of <.0001 to actual number

Hi,

Have you tried to use scientific format rather than fixed Dec?

jaboraws

Community Trekker

Joined:

Mar 29, 2016

Re: how to convert p value of <.0001 to actual number

Yes, I have tried all the different formats and different widths and decimal places.  It all just converts to "0".

Thanks though. 

martindemel

Staff

Joined:

Jul 10, 2014

Solution

Re: how to convert p value of <.0001 to actual number

The reason why you see 0e+0 is most likely that the number of leading zeros after the decimal is higher than what you asked to display. Then JMP or any other software can only represent what is given by the calculations which is 0 then.

However, you should be aware of floating point arithmetic and what it is capable of calculating.1e-17 usually is the point where a floating point number cannot differentiate from 0, which means every non-zero value smaller than 1e-17 will be interpreted in calcualtions as zeros. That's (within others) for what symbolic math is good for, because you use symbolic values to deal with that, and the maths behind will calculate further on with mathematical rules rather than actual numeric calculations. Just a side note