Borrar filtros
Borrar filtros

How to fix a matrix error

2 visualizaciones (últimos 30 días)
Emilia
Emilia el 11 de Dic. de 2020
Respondida: Daniel Pollard el 11 de Dic. de 2020
Hello,
I created a matrix and during there is an error, what was my mistake here.
Thanks for the helpers
n=4;
f=4*ones(1,n^2);
m=diag(f);
format short %Fixed decimal format with a total of 4 digits
j=0;
while j~=n^2
[m(j+1,j+2)]=-1;
[m(j+1,j+4)]=-1;
[m(j+2,j+1)]=-1;
[m(j+4,j+1)]=-1;
j=j+1 ;
end
A=m(1:n^2,1:n^2);
b=zeros(1,n^2);
b(1)=1;
b(n^2)=1;
x0 = (0:n^2);
L = tril(A,-1);
D = diag(diag(A));
U = -triu(A,1);
K=D+L;
J=K\U;
P=K\b;
x=J*x0+P;

Respuesta aceptada

Daniel Pollard
Daniel Pollard el 11 de Dic. de 2020
A (and consequently, L, D and U) is a 16x16 matrix. b is a 1x17 matrix. To fix this, either make A one bigger in each dimension, or make b one shorter. If you make b one shorter, then you need to also make x0 one shorter, because that is 1x17 as well.
n=4;
f=4*ones(1,n^2);
m=diag(f);
format short %Fixed decimal format with a total of 4 digits
j=0;
while j~=n^2
[m(j+1,j+2)]=-1;
[m(j+1,j+4)]=-1;
[m(j+2,j+1)]=-1;
[m(j+4,j+1)]=-1;
j=j+1 ;
end
A=m(1:n^2,1:n^2);
b=zeros(n^2-1, 1);
b(1)=1;
b(n^2)=1;
x0 = (1:n^2)';
L = tril(A,-1);
D = diag(diag(A));
U = -triu(A,1);
K=D+L;
J=K\U;
P=K\b;
x=J*x0+P;
There's no way for me to know if this produces the right output, but it runs without error now.

Más respuestas (0)

Categorías

Más información sobre Creating and Concatenating Matrices en Help Center y File Exchange.

Etiquetas

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by