topic Hadamard and associated BIB designs using IML in SAS/IML Software and Matrix Computations

Hadamard and associated BIB designs using IML

IanWakeling — Thu, 15 Mar 2012 18:22:59 GMT

I thought there might be some users here who would like to see how the hadamard function can be used to generate balanced incomplete block designs in IML.

The code attached implements combinatorial constructions for the designs rather than taking the iterative search approach that is possible with PROC OPTEX.

Hadamard and associated BIB designs using IML

Rick_SAS — Thu, 15 Mar 2012 18:42:53 GMT

Thanks for posting. I don't know much about this topic, but people who are interested in generating experimental designs should look at the collection of macros that use SAS/STAT, SAS/QC, and SAS/IML to generate all kinds of experimental designs, including ones that use Hadamard matrices. If you are interested in these topics, see http://support.sas.com/resources/papers/tnote/tnote_marketresearch.html, which includes a link to the MktBIBD macro, and lots more!

Hadamard and associated BIB designs using IML

IanWakeling — Fri, 16 Mar 2012 10:02:37 GMT

Thanks for posting the link Rick. I think the market research macros are using Hadamard matrices as a source of orthogonal arrays and fractional factorials, not to generate BIBDs. So while MktBIBD is a good tool for finding partially balanced designs, it will generally be quite bad at finding these Hadamard designs as it also uses the OPTEX approach. The point at which things start to break is around 19 samples, so

%MktBIBD(b=19,t=19,k=9,options=);

will find the balanced design with about 4 minutes CPU on my computer, while

print (sbibd(19));

with the IML program is virtually instantaneous. Any higher than 19 and you would have to be content with a sub-optimal design if you use MktBIBD.