My vectors appear to be the same length but I am still getting error for plot

Hi there, I am trying to do an iterative and random sampling best fit plot. I keep getting error, saying that "vectors must be the same length. My mat1 is 38 x 2, RP1 is 38 x 1 and Dmge is 38 x 1. Any suggestions

mat1 = [Dmge RP1];

for ii=1:10
    b = randsample(1:38,35); 
    A= 5500; B=0.19; C=2.3;
    goemp_fit1 = @(y)sum((y(1)*exp(-exp(-y(2)*(x(1,:)-y(3))))-x(2,:)).^2);
    coeff = fminsearch(goemp_fit1,[A B C]);

      A = coeff(1);
      B = coeff(2);
      C = coeff(3);

      y2 = A*exp(-exp(-B*(RP1-C)));

      y2_tp = transpose(y2);
      plot(mat1(b,2),y2,'-','Color',mcolour(ii,:))
      xlabel('Flow3');
      ylabel('Damage ($000USD)');
      title('Damage v Flow3');
  end

[madhan ravi]

Can you provide the mat1 details?

[KSSV]

How about x and y? You have not specified where/ which line is error.

[Naveed Hossain]

Thank you for asking that question. I found my error

Answer 1

[Walter Roberson]

b = randsample(1:38,35);

is going to return a vector of length 35.

      y2 = A*exp(-exp(-B*(RP1-C)));

with RP1 being a vector of length 38, is going to return a vector of length 38.

      plot(mat1(b,2),y2,'-','Color',mcolour(ii,:))

is going to use the 35 values in b to index rows in mat1, giving you 35 results. But y2 is 38 values.

I would suggest that you replace

      b = randsample(1:38,35);

with

     b = randperm(size(mat1, 1), length(RP1));