Plackett Burman algorithm

Question

Hi,

I like to be able to write a code to generate Plackett Burman orthogonal array for any arbitary number of factors and number of runs. Does any one know how JMP is generating the custom design for many binary continuous variable? Thanks

AT · Answer

Thanks Mark. I appreciate your help. I meant two level continuous factors. I have doen DOE with custon design and made a script that works fine. Now I want to be able to generate the same design matrix using the appropriate algorithm. Thanks

Mark_Bailey · Answer

First, I think that you mean two-level continuous factors instead of binary continuous factors. (Binary connotes categorical levels.)

Second, the Plackett-Burnham designs (irregular fractional factorial designs) are based on Hadamard matrices for generators, not generator words and rules (group theory) like regular fractional factorial designs.Custom design does not use generators or matrices but instead it uses the coordinate exchange algorithm by Nachtsheim, et. al. See the reference in Help > Books > Design of Experiments.

Plackett-Burnham designs accommodate two-level continuous and two- or three-level categorical factors for the main effects model. Larger designs might support the estimation of cross terms for interaction effects. The number of runs is constrained to be a multiple of 4, not just any number.

You can script making a design in JMP, including custom designs, using the DOE() function. Make an example interactively with Custom Design platform and then save a script to see the syntax.