I have generate the full factorial design using the function gen.factorial()at Rpackage AlgDesign and pass the results to optFederov() which willfind an optimum fractional design using the Federov algorithm.

The following code takes about 3 minutes to run on my Windows laptop. The example finds an approximate optimum fractional factorial design with 8 factors with 3, 4, 6 or 11 levels each, as you specified.

When I use optFederov(..., approximate=False)my Windows stopped.Could anybody explain what might be the reason? How to do this using SPSS syntax?

library(AlgDesign)levels.design = c(3,4,6,11,3,4,6,11)f.design <- gen.factorial(levels.design)fract.design <- optFederov(        data=f.design,        nTrials=sum(levels.design),        approximate=TRUE)