For some reason I can't use iem_tab's cross correlation object in one particular patchit is completely unresponsive. This is in spite of the fact that the patch in question is almost identical to another patch in which cross correlation works. The one change concerning iem_tab is that a different set of tables are being used. The tables in question are the same sizes in the same order as the ones in the working patch and they are populated, so it makes no sense to me whatsoever.

Iem_tab cross correlation suddenly won't work at all

Actually, I just realized it isn't working in the other patch, either. So basically, how do I make it work? It works in the help patch, but appears to do nothing outside of it.

I figured out that the problem arises when the tables exceed a certain size. The tables I was trying to correlate were rather large. So my question now is: is there some other way to efficiently perform a correlation between a pair of large tables, meaning tables with 400000 and 800000 indexes? Ideally, I would like to perform as many correlations per second as possible. I'm not sure if that's really going to be computationally feasible, though, unless I greatly reduce the size of the tables. Some help would be appreciated.

@Polaris Unsure but the first table must be larger then the second for it to work.
David. 
Thank you for your reply. In fact, the table sizes are correct. The problem is that it takes minutes for it to calculate the cross correlation. So I'm wondering if there's some other, faster way to do it.