matrix math problems , error in matrix size
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i have a rectangular matrix of size 18 by 3 and a column of 18 by 1, when I try to solve for the x matrix (3 by 1) it says I have incorrect sized dimensions to do the math, why? mat lab says the rows should agree and it should allow me to divide them using "/"
xx=[x_e; x_a; x_w];
NU=[lnu_e;lnu_a;lnu_w];
co=xx/NU;
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Accepted Answer
Paul
on 22 Oct 2022
Hard to say without without knowing anything about the data in the question. Based on the wording it should work as follows
A = rand(18,3); % 18 by 3
b = rand(18,1); % 18 by 1
x = A\b % solve for 3 x 1, note use of backslash
The result does not satisfy the matrix equation because there are more equations than unknowns
norm(A*x - b)
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More Answers (1)
Walter Roberson
on 22 Oct 2022
xx = rand(18,3);
NU = rand(18,1);
try
xx/NU
fprintf('/ worked\n');
catch ME
fprintf('well, / did not work\n');
end
try
xx\NU
fprintf('\\ worked\n');
catch ME
fprintf('well, \\ did not work\n');
end
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