About LU factorization

[DrD]

(06-04-2015 11:06 AM)salvomic Wrote:  so, is the Prime using Doolittle? Please, could it use *both* methods, to choose one? ;-)

For your matrix M1:=[[2,1,1],[4,−6,0],[−2,7,2]], I get:

L1:=LU(M1) = {[[1,0,0],[0.5,1,0],[−0.5,1,1]],[[4,−6,0],[0,4,1],[0,0,1]],[[0,1,0],[1,0,0],[0,0,1]]}

Since L1(1)=[[1,0,0],[0.5,1,0],[−0.5,1,1]] (Lower triangular, has one's in diagonal) it would be the Doolittle method.

By the way, I went through Gil Strang's MIT online classes. I really enjoyed them!