Problem with j in getG #55

Hi,

I'm using a genomic data set with 180K SNPs to create G matrices. I want to exclude around 3K of these SNPs from the calculation, so I used the j argument to include all other columns than these 3K. This gave a wildly different answer than when not excluding columns, with generally much larger entries than what we should be seeing.

This problem persisted even when I excluded just 1 single randomly selected SNP column (again, out of 180K SNPs, so this should have a large effect, right?). This also shows that the problem is not specific to the columns I wanted to exclude, but to excluding columns with j at all.

Luckily I was able to get around this issue by instead making a new BGData object where the unwanted SNP columns were not included in the first place, and then not specifying j in getG. This gave the expected/right answer, so there seems to be some problem with using j.

Thank you for the package, it is very helpful.