Regarding the limit on %. in J: Perhaps you should get a bigger machine? I tried the following just now on this machine, a run-of-the-mill Celeron (2.8 GHz, 512 MB):
x=: 100 100 [EMAIL PROTECTED] 0 NB. random real matrix 6!:2 'y=: %. x' NB. invert it 0.0141401 >./|, (=i.100) - x +/ .* y NB. how accurate? 1.64729e_14 If numerical instability is a problem, there is the option to use rational numbers, that is, invert x: x instead of x . It'd be much more expensive in space and time but %.x: x would find THE inverse if there is one. ----- Original Message ----- From: Henning P. Jørgensen <[EMAIL PROTECTED]> Date: Monday, January 15, 2007 7:26 am Subject: [Jgeneral] Invert max and LAPACK > On my system it is possible to invert up to 87*87 matrices with J > and widows on a PC. > I believe excell goes to something like 64*64. > Of cause SAS and GAMS can go higher, but > > Is it possible to get J to invert larger matrices? May be as Sparse? > > As you may have guessed the LAPACK lab did not work on my PC. > I can download it to the add on area, but a call from the LAPACK > lab results in an error. Is there a solution to that? > > Error in jijs_jctrl_fkey.. > > > Best wishes > Med venlig hilsen > > Henning P. Jørgensen > Lektor, Institut for Miljø- og Erhvervsøkonomi > > Tlf. 6550 4187 > Fax 6550 1091 > Web http://www.sam.sdu.dk/ansat/hpj > Adr. Niels Bohrs Vej 9, 6700 Esbjerg > > SYDDANSK UNIVERSITET > _______________________________________________________________ > Niels Bohrs Vej 9-10 * 6700 * Esbjerg * Tlf. 6550 1000 * www.sdu.dk ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
