Register to reply

Asking about matrix division

by Sledge
Tags: division, matrix
Share this thread:
Sledge
#1
Mar17-14, 08:36 AM
P: 1
Is it possible to compute matrix (A/B) without first finding the inverse of matrix B but ending with EITHER { A * (Inverse of B) } OR { (Inverse of B * A }....i think i discovered the trick
Phys.Org News Partner Mathematics news on Phys.org
'Moral victories' might spare you from losing again
Fair cake cutting gets its own algorithm
Effort to model Facebook yields key to famous math problem (and a prize)
D H
#2
Mar17-14, 09:11 AM
Mentor
P: 15,067
Another way to write ##X=A/B \equiv AB^{-1}## is ##XB=A##. This has a unique solution X if B is not singular. You can solve for X in XB=A using Gaussian elimination.

Another way to write ##X=B \backslash A \equiv B^{-1}A## is ##BX=A##. This, too, has a a unique solution X if B is not singular. You can solve for X in BX=A using Gaussian elimination.

What if B is singular? The standard approach is to use the pseudo-inverse, and now you have but no choice to compute that inverse, typically via singular value decomposition.


Register to reply

Related Discussions
Transition from lower division to upper division as a physics major Academic Guidance 0
Difficulty of lower division courses vs. upper division (undergraduate) Academic Guidance 10
Simple matrix division in Matlab Programming & Computer Science 2
Optimal division of a matrix for processing General Math 4
Matrix Division? General Math 5