Generate DoE matrix and test plan

I would like to generate both a test matrix and a test plan using DoE methodology. I already found these functions: hadamard (x); ff2n(x) and fracfact(...) But, the 1st function doesn't give me a clear vision of the experimental sequence and of the existing aliase. I can obtain this vision by using the function fracfact, where I can define the aliases. But the output of this function give just the combinaison of -1, +1 of the parameters. I don't have the complete DoE matrix for te further DoE analysis. Moreover, I didn't find the way to generate a full factorial design. The fullfact function doesn't do it.

Additionally, for experimental data extraction purpose, I would like to replace in the matrix, the -1 and +1 values by the respective extrema of parameters values.

Thanks for your help

Answer 1

[Tom Lane]

Phillippe, you are right that the Statistics Toolbox offers a collection of DOE tools rather than a beginning-to-end DOE application. Here's how to use some of those tools. You can generate a full factorial design for four factors each taking two values as follows:

   design = fullfact([2 2 2 2])

For historical reasons, this codes the two levels as 1 and 2. The fracfact function codes them as -1 and 1. Here's how to use that function to get the equivalent design and its confounding pattern:

   [design,confounding] = fracfact('a b c d')

Here's how to generate a 2^(4-1) design:

   [design,confounding] = fracfact('a b c abc')

Here's how to change the limits in the first column to other limits that you specify (you could repeat for other columns or loop over them):

   limits = [5 10];
   design(:,1) = limits(1) + (limits(2)-limits(1))*(1+design(:,1))/2

Finally, you may want to randomize the order of runs when you carry out the experiment. Here's how to do that:

   order = randperm(8)
   design = design(order,:)

Answer 2

[Rick Rosson]

Do you have access to the Statistics Toolbox? If so, there are some functions provided there related to DoE and SPC.

HTH.

Rick

Answer 3

[Philippe]

Yes, I have this toolbox, where the functionshadamard(), ff2n() and fracfact() are included. But, as I mentioned above, these function doesn't give me what I need. But, may me I didn't see some others. And I tried ! Thansks.