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Occasional Contributor

## Re: Mixture Design 14 factors or more... some needs to be equal to each other...

So I need just to play with it a little bit more to get used to it.

Yeah I noticed the techinal and mathematical terms in a preview.

@markbailey thanks for you recommendation. I will look into it aswell.

Now that people are still using this subject! A different question but with the same scenario.

I can open another discussion if that is more easier....

Same scenario but this time the ratio is the only constant value.

C1 liquid reacts with C2 liquid in a ratio 100:75

So the formula will be:      4*C1 liquid = 3 C2 liquid

As far as I understand from https://www.jmp.com/en_in/events/ondemand/mastering-jmp/mixture-designs.html

The constrain will become:

4*C1 liquid -3 C2 liquid </= 0

4*C1 liquid -3 C2 liquid >/= 0

The other constrain is just like last time, that all ingredients for component 1 is 50% and all the ingredients for component 2 is 50% of the total blend.

The picture is a little bit small now... sorry. (just to be sure it can also be found in the appendix.

For some weird reason I get now "Optimal designer failed to converge."

Have I filled in something wrong here?

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Staff

## Re: Mixture Design 14 factors or more... some needs to be equal to each other...

When you start constraining your components this much and JMP fails to find a design, my first question is always: do you even have a feasible experimental region left? Look at your component constraints along with these additional constraints. Is there a viable region to experiment over?

Dan Obermiller
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Occasional Contributor

## Re: Mixture Design 14 factors or more... some needs to be equal to each other...

I understand, I had something in my mind and I probably need to rewrite the components values.

I'm sure it is possible, I just need to check my factors again.

I have simplify it and then it was possible. See picture down here.

Due to the ratio there is not really a plane, but more like a line were the optimal can be reached.

That line is in an area of 0 by 0.5.

C1 liquid and C2 liquid are reacting with a ratio of 100:75. In this example in a range of 0 bij 0.5.

(0 is not really what I want, because it needs to react, but I wanted to see if it was possible.)

The optimal will be checked with every Filler ingredients. So GGREY006A... etc.

So how I see it, JMP can check a line area.

And yes I noticed my ratio fault here.

It's now C1 liquid : C2 liquid

75   :  100

And I wanted C1 liquid: C2 liquid

100    :    75

I need to swap the 4 and the 3 around.

I'm going to play a little bit more with JMP.

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Occasional Contributor

## Re: Mixture Design 14 factors or more... some needs to be equal to each other...

Made it!   Sorry for the spam... Thanks for all the help and replies!

Community Trekker

## Re: Mixture Design 14 factors or more... some needs to be equal to each other...

Generally doesn't mean your n = 1 example...LOL. Really most papers and texts you read describe mixture designs as having few variables. But there are many approaches to getting things done. One of my favorite quotes is. “Two equally competent investigators presented with the same problem would typically begin from different starting points, proceed by different routes, and yet could reach the same answer. What is sought is not uniformity but convergence." (Box, Hunter, Hunter).
Cheers.
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Community Trekker

## Re: Mixture Design 14 factors or more... some needs to be equal to each other...

Yes, John A. Cornell is recognized as one THE experts on mixture designs.  I recommend his papers " Embedding Mixture Designs inside Factorial  Experiments", "Mixture Experiment Approaches: Examples, Discussion, and Recommendations".  Also Ron Snee has some good papers "Screening Concepts and Designs for Experiments with Mixtures" and Design and Analysis of Mixture Experiments".

Enjoy!