missing linearalgebra functions



Thank, Barton, for your reply. I have confirmed that yes, that's the case... cholesky works great for numerical, but doesn't work for symbolic. That's actually not at all a limitation to what I need to accomplish.

Best,
Mark


From: Barton Willis [mailto:willisb at unk.edu]
Sent: Thursday, September 13, 2012 2:54 PM
To: Kust, Mark P.; fateman at eecs.berkeley.edu
Cc: maxima at math.utexas.edu
Subject: RE: [Maxima] missing linearalgebra functions

Th Cholesky code doesn't work for symbolic cases, I think. Try this (loading linearalgebra isn't needed):

  (%i21) cholesky(matrix([14,32,596],[32,77,1217],[596,1217,36245]));
  (%o21) matrix([sqrt(14),0,0],[32/sqrt(14),3^(3/2)/sqrt(7),0],[596/sqrt(14),-(113*sqrt(3))/sqrt(7),5*6^(3/2)])

  (%i22) %.transpose(%);
  (%o22) matrix([14,32,596],[32,77,1217],[596,1217,36245])

--Barton
________________________________

T


So, as you can see, the cholesky function is not loaded. This is confirmed by the simple example I introduced above:

(%i3)   cholesky(matrix([1, p12, p13], [p12, 1, p23], [p13, p23, 1]));
Unable to find the Cholesky factorization
-- an error. To debug this try: debugmode(true);

Actually, what this shows is that the cholesky function IS loaded, since it gives an error message.
It was unable to find the factorization though. I have not looked at your matrix at all.




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