# Solving a system of linear equations with lots of o coefficients.

3 views (last 30 days)
Emily Pierce on 18 May 2022
Answered: Bjorn Gustavsson on 18 May 2022
I have a matrix system of linear equations that look somthing like this were u is a vector of 7 unknowns
I have tried useing linsolve to solve this but My solution is coming out as 0. I am unsue how to fix this.
Thank you for your time and help!
12 8 0 0 0 0 0
-4 12 8 0 0 0 0
0 -4 12 8 0 0 0 (u) =
0 0 -4 12 8 0 0
0 0 0 -4 12 8 0
0 0 0 0 -4 12 8
0 0 0 0 0 -4 12
12
0.7
0.4
1
1.2
1,7
-25

Bjorn Gustavsson on 18 May 2022
Matlab is designed to solve systems of linear equations. It is one of the fundamental operators of its matrix-algebra:
% u = M*x;
% that has a solution:
x = M\u;
% Check #1:
M*x - u
% Check #2:
[U,S,V] = svd(M);
disp(diag(S))
Since you ask this question this way I deduce that you are reasonably new working with matlab. If that conclusion is close enough to correct, then you might consider browsing through the onramp material, it is an overview-introduction type presentation/course thing that is designed to get you up to speed ASAP. My understanding is that if you go through the parts you find relevant there and then browse/look through the help and documentation on things you'll get up to speed faster than by any other method.
HTH