Warning: Matrix is singular to working precision.
1 vue (au cours des 30 derniers jours)
Afficher commentaires plus anciens
writing a 5x5 matrix for spatial analytic geometry. the goal is to calculate for 5 unknown forces using the numbers an excel document has provided. i am getting an error message saying "Matrix is singular to working precision." i am very new to matlab, excuse me if it has a simple solution.
clc
%axial/corner weight
syms F1 F2 F3 F4 F5
Fb= 0;
Fcw = 1172.112806;
Fn = 689.4781211;
A=[1 1 1 1 0 ; 1 1 1 1 1 ; -1 -1 -1 -1 1 ;-778.8791468 -346.4077963 -149.2503011 -149.2503011 -163.019189 ; 16.28468788 201.1553234 34.19171497 34.19171497 115.3981707 ];
x=[F1 ; F2 ; F3 ; F4 ; F5]
b=[-Fb ; -Fcw ; -Fn ; 0 ; 0];
x=A\b;
0 commentaires
Réponses (2)
Fabio Freschi
le 11 Août 2021
Modifié(e) : Fabio Freschi
le 11 Août 2021
The matrix is singular because the first three rows are linearly dependent. For example you can obtain row 1 as
I guess there is something wrong in your formulation.
BTW: you don't need to use the symbolic toolbox here, because all entries of A and b are numeric. Symply get x from the solution of the system
% params
Fb= 0;
Fcw = 1172.112806;
Fn = 689.4781211;
% (singular!) coefficient matrix
A=[1 1 1 1 0 ; 1 1 1 1 1 ; -1 -1 -1 -1 1 ;-778.8791468 -346.4077963 -149.2503011 -149.2503011 -163.019189 ; 16.28468788 201.1553234 34.19171497 34.19171497 115.3981707 ];
% rhs
b=[-Fb ; -Fcw ; -Fn ; 0 ; 0];
% solution
x=A\b;
0 commentaires
Chunru
le 11 Août 2021
A=[1 1 1 1 0 ; 1 1 1 1 1 ; -1 -1 -1 -1 1 ;-778.8791468 -346.4077963 -149.2503011 -149.2503011 -163.019189 ; 16.28468788 201.1553234 34.19171497 34.19171497 115.3981707 ];
A
Your matrix A has at least two linearly dependent colomns (3 & 4). Therefore the matrix is singular and the inverse cannot be evaluated. Or Ax=b has no solution.
0 commentaires
Voir également
Catégories
En savoir plus sur Linear Algebra dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!