Conditional constraints for continuous factors?

JerryFish

Say I've got a DOE with 2 continuous factors (X1 and X2).  It's pretty clear how to set up linear constraints if I want to constrain my design region to make a convex polygonal shape something like this:

 

 

How do I do a "conditional constraint" to make a convex polygon, like this?

 

 

So I've got conditional linear constraints (for X1 between 0 and 1, use this line, for 1 to 2, use that line).

 

I realize this presents modeling and profiling problems for the excluded region.  Just anticipating a potential customer need here.

 

Thanks for any suggestions!

 

 

JerryFish

It appears that "Use Disallowed Combinations Script" might get the job done, but I'm not able to get it to work.  For the concave polygon shape shown in the original post, the script I used was:

 

(X1 >= 0 & X1 < 1 & X2 >= X1) & (X1 >= 1 & X1 <= 2 & X2 >= 2 - X1)

 

But the resulting I-Optimal design space looks (RSM model, 20 trials) like this:

 

 

Also, when I go back to the Script, I notice that the first set of parens have been removed so the script now looks like:

X1 >= 0 & X1 < 1 & X2 >= X1 & (X1 >= 1 & X1 <= 2 & X2 >= 2 - X1)

 

Anybody know what's up?