hmmm....It seem that's a powerful software,but it doesn't say how to pick the best ( = superior and the most stable ) parameters among the parameters combinations from the optimization,especially when parameters are more than 3.
The WFO should be repeated several times,for example,the whole data range is from 1991.1.1 to 2005.7.11,the first in-sample test is from 1991.1.1 to 1998.12.31,then the software should pick the best ( = superior and the most stable ) parameters combination on this period and perform it on the first out of sample test (from 1999.1.1-1999.12.31),then record the result;then test on the second in sample period(from 1992.1.1 to 1999.12.31) with all of the parameters combinations,and picks the best ( = superior and the most stable ) parameters combination,and perform it on the period from 2000.1.1 to 2000.12.31,and record the result,...
The most problem is how to pick the best ( = superior and the most stable ) parameters combination.