Re: Multivariate Statistical Distance (MSD)

rshehadah · May 13, 2019 02:28 PM

Hi,

Is there a way to calculate the multivariate statistical distance (MSD) in JMP? This calculation will help understand the difference between dissoulutions.

Thank you,

Rami

Mark_Bailey · May 13, 2019 03:03 PM

There are many ways to calculate a distance. A distance measure is the basis for many multivariate methods. What method are you thinking of using?

Dissolution is an event, an outcome. Are you measuing the dissolution over time? Are conditions varying for each run?

rshehadah · May 13, 2019 03:16 PM

Trying to calculate the Mahalanobis Distance.

For example I have 2 tablets that have different dissoultion curves. I want to understand if they are the same or different.Each tablet is measured every 5 mins to understand the % of drug release.

I can not use the F2 because there is alot of variablty, so I believe the Mahalanobis Distance is the correct method.

Mark_Bailey · May 13, 2019 03:24 PM

The Mahalanobis distance is calculated in Analyze > Multivariate Methods > Multivariate. Click the red triangle and select the sub-menu for outliers.

rshehadah · May 13, 2019 06:14 PM

Does this just look for outliers or will it help me understand if the tablets are different from each other?

Mark_Bailey · May 14, 2019 09:59 AM

That is a different question. You asked how to calculate a multivariate distance. It seemed to me that you knew what you wanted to do but you did not know how to use JMP to do it. Now you are asking how to judge if tablets are different. I don't understand what you want.

Mark_Bailey · May 13, 2019 03:14 PM

You can select Help > Help in JMP. Type "distance" in the search box. You will see many results related to this topic. Which one is the analysis that you want to do with dissolution?

rshehadah · May 13, 2019 06:51 PM

@Mark_Bailey

I ran it through JMP and this is what I got. My variables are timepoint and manufacter. From the result it seems like the dissoulstion curves are the same?

Mark_Bailey · May 14, 2019 10:09 AM

"From the result it seems like the dissoulstion curves are the same?" This result is the distance that you requested for your decision.

rshehadah · May 14, 2019 01:28 PM

Hi, @Mark_Bailey ,

Thank yiu for your replies.

My problem is that I want to understand if two dissoultion curves are similar or different. One way of doing this is running the Mahalanobis distance, which you helped me do in JMP.

I am having a hard time understanding the results of the Mahalanobis distance output. There is no indicator that I can see that tells me they are the same or different.

Thanks,

Rami