How to make a function to plot values of a Matrix?

For a linear system A*x = B where A and B are known

Yv = [-Y 0 0; 0 Y 0; 0 0 Y];
A = [5 -4 4; -5 4 3; 5 3 1];
AY = A + Y;  % ALSO TRIED USING: Instead of AY Y= [(5-Y) -4 4; -5 (4+Y) 3; 5 3 (Y+1)]
B = [1; 4; -2;];

inverseA = inv(AY);
x = inverseA*B; %vector x must satisfy 

for n = 1:size(B)    

    xr = x(n);
  %     resultxt = 'Value %2.0f of vector x is %6.3f \n' ;
  %     fprintf(resultxt, n, xr)
      a = x(1);
      b = x(2);
      c = x(3);

This returns me x1 x2 and x3 for the matrix in forms of a b and c respectively. I am trying to plot the values of x1 for

Y = linspace (1,12)

which does not work given that the (vector) sizes don't match. Any ideas? Thanks

Answer 1

[KSSV]

Y = linspace(1,12) ;
a = zeros(size(Y)) ;
b = zeros(size(Y)) ;
c = zeros(size(Y)) ;
for i = 1:length(Y)
    Yv = [-Y(i) 0 0; 0 Y(i) 0; 0 0 Y(i)];
    A = [5 -4 4; -5 4 3; 5 3 1];
    AY = A + Y(i);  % ALSO TRIED USING: Instead of AY Y= [(5-Y) -4 4; -5 (4+Y) 3; 5 3 (Y+1)]
    B = [1; 4; -2;];
    inverseA = inv(AY);
    x = inverseA*B; %vector x must satisfy 
    % x = A\B ;
    for n = 1:size(B)    
        xr = x(n);
        %     resultxt = 'Value %2.0f of vector x is %6.3f \n' ;
        %     fprintf(resultxt, n, xr)
        a(i) = x(1);
        b(i) = x(2);
        c(i) = x(3);
    end
end
hold on
plot(Y,a,'r')
plot(Y,b,'b')
plot(Y,c,'g')
legend([{'a'}, {'b'},{'c'}])

[Alexander Holman]

Thank you so much! Is the part where

Yv = [-Y(i) 0 0; 0 Y(i) 0; 0 0 Y(i)];

Really necessary?