Problems with mldivide,\

Hello guys,

i have a A*x= B equation and filled my matrices with random numbers.

I used \ to get the results for x.

But when i use the calculated x to multiplicate with A, the result should be the matrix of B. In B and C are different matrices, which i dont understand.

Do i have any mistakes here?

A=rand(183,4);
B=rand(183,1);
x=A\B;
C=A*x;

Answer 1

[Walter Roberson]

Your system is over-determined. mldivide is going to do a least-squared fitting. The reconstruction should not be expected to be the same as the original data (not unless the original data can be explained in 4 or fewer linear terms.)

[Aj]

Thanks for the answer!

How can i fix this? Is there an alternative to mldivide?

[Walter Roberson]

You cannot fix this. You are asking to explain 183 or more independent values with only 4 coefficients.