Mahalanobis distance in JMP differs from other methods

[#1]

Hi,

I am comparing Mahalanobis distance calculated by JMP vs. one reported in other tables using their software. The JMP reports for MD 2.35 +/- .54 vs. 1.23 +/- 0.68 . I was wondering if there is anything special about JMP. I have 30 data points with 6 variables.

I appreciate any comments. Thanks

[#2 · Accepted solution]

Here is the calculation used in JMP for Mahalanobis, taken from 

     Help==>Books==>Multivariate Methods

Is it different from your undefined product?

[#3]

Thanks Jim for the reply and definition of MD in JMP. The one I like to use is Mahalanobis distance defined in Mahalanobis Taguchi System (MTS). I have attached the definition in the attached file. It looks like there are differences. 

Anyone has used MTS method in JMP? Thanks

[#4]

More dodgy maths from Genichi Taguchi?