I have a data set that looks like:   Direction CUSTOMER_ID REGION reg_A reg_B NET_SUPPLIED 1 a A 1 . 2 1 a B 1 . 3 1 b A 1 . 4 1 b B 1 . 5 2 a A . 4 6 2 a B . 4 7   and I want to delete the rows where the value in "region" coincides with a value of "." in that region, unfortunately I have a large number of regions and not all will show up in every query so I cant just list each region in a bunch of if statements is there any way to do a single if statement that looks like:   if "reg_"+value(region)=. then delete;   if not are there any methods other than just writing a long list of if statements?   Thanks!  ... View more

I have a data set that has the form:   a=N x M data set (N>M) and b=NxP data set  which forms an equation  aX=b,    to solve this I am using the IML echelon function, but unfortunately my data does not seem to be perfect (possible rounding errors) as the echelon over solves my matrix [a|b] and row reduces too far, is there a possible way to identify what rows to pick so that I could do an inversion solve or to truncate the variables to ensure rounding errors are not an issue?     ... View more