tree b1aaa58e11763b05c5a5fb35dd240d0841c9ba80
parent 1b7d9ca04ac9c91c480304733efcffbc0ac1d550
author Dan Kortschak <dan@kortschak.io> 1713384159 +0930
committer Dan Kortschak <dan@kortschak.io> 1713429838 +0930
gpgsig -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEExlqSvVyHJADMC2JWRYF7rZWOPwwFAmYg3U4ACgkQRYF7rZWO
 PwwRJxAAi4yiQhRfw22CxVzw9AuWAN+Qs/LNFAWb7w33UkkD5AWI1hZCmUpviCaP
 wkFgCntsrHVdbfkAJLZ/+jVavsb7gUBD/zLfOaNdVHaezg+sYjXNjmd7ry7ugJEw
 0FOgcywaIXtij942KDx8NBtlba30U2qBBNuGe6FR3Gkszx2ADPNbsvmbdbeiyFX+
 op2AX/SjDZbjmFSlDtPqp/H0/jzupKti/PQ0lLEIYiYfipWYs70f7o6zTke1XTeO
 Ow2yfeFyizWhmOPKt25ksqEzQWbxEmkD5V9+3Xpa4tjdcAQmHvliGQto5fNLgTCR
 oWJqNgoNy4Rx+PgvyNp/D6dzRytgI8UA8r6851Dw28mcvjBQx8mFOQBrDx/flaAs
 s0HD2BkOcahX121ZixV/Rf7qM+L4/v4vOxzMPiPhuzTLNu4ORzcL/MWRmQ3QV/f4
 PSekmQ+HRTLau/jdTqrl8nBLxwfEA7eamluCijnCvB9LnYGR1ee6FsklEYAiAhMT
 a9/akPGWjOA8znoXQEiYu//ZCnq0pYlDVQcizwgngAWf+I9oq/vkFlKymojJhaaF
 jwcj4zOprtYja/ofe66xuh/P4MLt3Y50zhjw3ASm2i7Be4/THVrlCdVetCvzb3Jz
 /FRXtN0pExnCFJ9xUUh+euJhg3aaCQPqCKrhnWtG8idpXbdhcRU=
 =dIUm
 -----END PGP SIGNATURE-----

mat: calculate Q lazily when calling QR.ToQ

When a matrix is very tall, calculating Q will currently allocate a large Q at
the end of the factorisation, even if it is not going to be used. The eager
calculation was intended to prevent repeated re-calculation of Q when it is
used. So move the Q calculation to ToQ, but make it conditional on the stored
Q value being empty, and empty Q at the end of the factorisation.