Solve matrix equations using loop

Hello everyone!

I have a matrix A(3x3)

A= (2 10 15

3 5 -7

3 -2 -2 )

And Matrx B (3x1)

B = (B1

B2

B3)

Matrix C (3x1), where all values are equal to each other

C= (C1

C1

C1)

So, I need using loop, solve the equations and find the values of C1, B2 and B3. B1 is known for me, and has 125 elements. For each B1, I have to find C1, B2 and B3 respectively

Solve the equation A*B=C

Thank you in advance!

[Ghazwan]

what is the equation you are trying to solve?

[Alina Abdikadyr]

A*B=C

[Torsten]

Didn't you like my solution ?

https://de.mathworks.com/matlabcentral/answers/1816340-extract-values-from-one-matrix-and-with-iteration-solve-the-system-of-linear-equations?s_tid=prof_contriblnk

Answer 1

[Chunru]

The equations you have:

You want to solve it for , and . You need to rearrage the equations:

Now you solve this new system of equations with unknowns as :

A = [  2 10  15
      3   5  -7
      3  -2  -2 ];
Anew = [-ones(3, 1)  A(:, 2:3)];
AnewInv = inv(Anew);

b1 = rand(5,1);   % rand(125,1) or your data
for i=1:length(b1)
    bnew = -b1(i)*A(:, 1);
    res = AnewInv*bnew    %[c1; n2; b3]
end

res = 3×1

0.9814 0.0096 0.0134

res = 3×1

1.8311 0.0178 0.0250

res = 3×1

0.9554 0.0093 0.0130

res = 3×1

1.8897 0.0184 0.0258

res = 3×1

0.4087 0.0040 0.0056