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I am trying to create a design with a 3 component mixture with an additional process temperature factor. If you have over 50% of component 1 in the mixture the low process temperature does not work.  JMP does not allow to use constraints on mixture designs does anyone know of a good work around? 

Thanks,

Pete

Re: Constrained Mixture Design

Oh never mind I understand now.  Putting in those interactions would be the same as the main effects since they would be confounded.

Re: Constrained Mixture Design

Hey Ryan,

Thanks for the script.  One issue if I add interactions between the mixture components and the reaction temperature it fails to converge.  Any suggestions?

Re: Constrained Mixture Design

Glad that works!

I should have mentioned, you should remove the intercept term from the model when creating it (otherwise the diagnostics go all crazy).

Cheers,

Ryan

Re: Constrained Mixture Design

Thanks Lou,

and thanks to Ryan as well.

I think this work around will work nicely. 

Re: Constrained Mixture Design

Hi Peter,

Spoke with Ryan L and he suggested entering all your factors as discrete numeric and utilizing the constraints on them. You will need to recode the table to reflect the column properties accordingly but it is a workaround.

DOE(

       Custom Design,

       {Add Response( Maximize, "Y", ., ., . ),

       Add Factor( Discrete Numeric, {0, 0.25, 0.5, 0.75, 1}, "mix1", 0 ),

       Add Factor( Discrete Numeric, {0, 0.25, 0.5, 0.75, 1}, "mix2", 0 ),

       Add Factor( Discrete Numeric, {0, 0.25, 0.5, 0.75, 1}, "mix3", 0 ),

       Add Factor( Discrete Numeric, {0, 1, 2}, "temp", 0 ),

       Set Random Seed( 225889679 ), Number of Starts( 5492 ), Add Term( {1, 0} ),

       Add Term( {1, 1} ), Add Term( {1, 2} ), Add Term( {1, 3} ), Add Term( {1, 4} ),

       Add Term( {2, 1} ), Add Term( {2, 2} ), Add Term( {2, 3} ), Add Term( {2, 4} ),

       Add Term( {3, 1} ), Add Term( {3, 2} ), Add Term( {3, 3} ), Add Term( {3, 4} ),

       Add Term( {4, 1} ), Add Term( {4, 2} ), Add Alias Term( {1, 1}, {2, 1} ),

       Add Alias Term( {1, 1}, {3, 1} ), Add Alias Term( {1, 1}, {4, 1} ),

       Add Alias Term( {2, 1}, {3, 1} ), Add Alias Term( {2, 1}, {4, 1} ),

       Add Alias Term( {3, 1}, {4, 1} ), Set Sample Size( 30 ),

       Disallowed Combinations( mix1 + mix2 + mix3 != 1 | mix1 >= 0.5 & temp <= 0.5 ),

       Make Design, Make Table}

);