You can write qrfact(X)[:Q]'y and sum the squares of the last n-k terms, but A_ldiv_B!(QR,y) should return the whole y including the Q2'y part and then let \ do the slicing.
2014-04-08 0:11 GMT+02:00 Simon Kornblith <si...@simonster.com>: > (To clarify, I mean the sum of the squared residuals, and there's a ^2 > missing below.) > > > On Monday, April 7, 2014 5:48:49 PM UTC-4, Simon Kornblith wrote: >> >> Is there a way to get the least squares residuals for qrfact(X)\y without >> having to compute X*beta, as is given by gels? I believe this should be >> ||Q2'y||; Q2'y appears to be computed but explicitly zeroed in A_ldiv_B!. >> >> Simon >> > -- Med venlig hilsen Andreas Noack Jensen