CHEN 3201 Lecture Notes - Lecture 14: Lu Decomposition, Dimensionless Quantity, Gaussian Elimination
24 Feb 2015
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Files we turn in must be self-containedthat"s why we do function. Script refers to things in the function as well as things in the memory. Gauss elimination: n3 + n2 =~ n3 (approximate #s) Banded gauss elimination (everything is stuck a certain distance around the diagonal): np 2 + np =~ np2 all of the above were for single system. A common problem is that we want to solve a system many many times where the matricies are (n x n), (n x m) and (n x m) respectively. Simultaneous gauss elimination e. g. a bunch of forcing functions. - > key question only have to go up to the dashed lines, don"t go past them. Time to solve: n x n x (n+m) = n2(n+m) =~ n2m where m >> n. Rewrite as we want to decompose the matrix a which becomes define (change of variable)
