Post Reply 
About LU factorization
06-04-2015, 02:12 PM
Post: #15
RE: About LU factorization
I get:

M1:=[[2,1,1],[−2,7,2],[4,−6,0]]; // Your matrix input ...
L1:=LU(M1); // --> {[[1,0,0],[−0.5,1,0],[0.5,1,1]],[[4,−6,0],[0,4,2],[0,0,−1]],[[0,0,1],[0,1,0],[1,0,0]]}

L1(1)*L1(2)/L1(3); // --> [[2,1,1],[−2,7,2],[4,−6,0]] ...Your matrix back again

My list (L1) is simply the Lower Triangular, Upper Triangular, and Permutation matrices, which is what the help description states.

You get:

M1:= [[2,1,1], [-2,7,2], [4,-6,0]]; // Same matrix as above
LU(M1); // -> {[1,2,3], [[1,0,0], [-1,1,0], [2,-1,1]], [[2,1,1], [0,8,3], [0,0,1]]}

If you set L1 to your list, then L1(2)*L1(3) returns your original matrix.

There's a different format in our list results, you get a vector and the Lower and Upper triangular matrices. Something seems to have changed in the versions, but both results seem to be okay.

-Dale-
Find all posts by this user
Quote this message in a reply
Post Reply 


Messages In This Thread
About LU factorization - salvomic - 06-04-2015, 09:10 AM
RE: About LU factorization - Paul Dale - 06-04-2015, 09:18 AM
RE: About LU factorization - salvomic - 06-04-2015, 09:52 AM
RE: About LU factorization - Tugdual - 06-04-2015, 10:15 AM
RE: About LU factorization - Paul Dale - 06-04-2015, 10:22 AM
RE: About LU factorization - Tugdual - 06-04-2015, 10:36 AM
RE: About LU factorization - DrD - 06-04-2015, 10:31 AM
RE: About LU factorization - DrD - 06-04-2015, 10:45 AM
RE: About LU factorization - salvomic - 06-04-2015, 11:06 AM
RE: About LU factorization - DrD - 06-04-2015, 11:30 AM
RE: About LU factorization - salvomic - 06-04-2015, 12:05 PM
RE: About LU factorization - salvomic - 06-04-2015, 12:48 PM
RE: About LU factorization - DrD - 06-04-2015, 01:31 PM
RE: About LU factorization - salvomic - 06-04-2015, 01:36 PM
RE: About LU factorization - DrD - 06-04-2015 02:12 PM
RE: About LU factorization - salvomic - 06-04-2015, 02:19 PM
RE: About LU factorization - DrD - 06-04-2015, 02:19 PM
RE: About LU factorization - salvomic - 06-04-2015, 02:22 PM
RE: About LU factorization - Werner - 06-04-2015, 04:57 PM
RE: About LU factorization - Gerald H - 06-04-2015, 05:10 PM
RE: About LU factorization - salvomic - 06-04-2015, 05:10 PM
RE: About LU factorization - salvomic - 06-05-2015, 08:15 PM
RE: About LU factorization - Claudio L. - 06-05-2015, 08:38 PM
RE: About LU factorization - salvomic - 06-05-2015, 09:00 PM
RE: About LU factorization - Claudio L. - 06-08-2015, 01:12 PM
RE: About LU factorization - salvomic - 06-08-2015, 01:15 PM
RE: About LU factorization - parisse - 06-07-2015, 06:42 PM
RE: About LU factorization - salvomic - 06-07-2015, 07:20 PM



User(s) browsing this thread: 1 Guest(s)