Subscript indices must either be real positive integers or logicals.???

Dear all,

I have defined the following function, where E is a 2-by-1 vector, Vn 2-by-2 matrix, c, u, sig_u_sn, sig_e_sn, gbar, all positive scalars. For example, I try the function with

[.149; .1448], [.02 0; 0 .009], .075, .15, .0004, .0004, 1

If I initialize E, Vn, c, u, sig_u_sn, sig_e_sn, gbar as above and run the code in the function, the code runs fine. BUT if I run the function using above, I get

"Subscript indices must either be real positive integers or logicals."

I googled around, but I'm really not sure why I get that message in my case. I'd really appreciate any and all helps. Thank you so much in advance!

Best, John

The function code below:

function y = y(E, Vn, M, c, u, sig_u_sn, sig_e_sn, gbar)

if c > 1.6*u*M^2

      error('please try again');

end

xb = min(2*M*sqrt(2*max(u - gbar*sig_u_sn, 0)/c), 1);

y = zeros(1, 3);

if xb > 0

      if sizecon(0, E, Vn, M, c, u, sig_u_sn, sig_e_sn, gbar) <= 0
          y(1) = 0;
      elseif sizecon(xb, E, Vn, M, c, u, sig_u_sn, sig_e_sn, gbar) <= 0
          x0 = xb/2;
          f = @(x) sizecon(x, E, Vn, M, c, u, sig_u_sn, sig_e_sn, gbar);
          y(1) = fsolve(f, x0);
      elseif xb < 1 && sizeunc(1, E, Vn, M, c, u, sig_u_sn, sig_e_sn) <= 0
          x0 = (xb + 1)/2;
          f = @(x) sizeunc(x, E, Vn, M, c, u, sig_u_sn, sig_e_sn);
          y(1) = fsolve(f, x0);
      else
          y(1) = 1;
      end
  else
      if sizeunc(0, E, Vn, M, c, u, sig_u_sn, sig_e_sn) <= 0
          y(1) = 0;
      elseif sizeunc(1, E, Vn, M, c, u, sig_u_sn, sig_e_sn) <= 0
          x0 = 1/2;
          f = @(x) sizeunc(x, E, Vn, M, c, u, sig_u_sn, sig_e_sn);
          y(1) = fsolve(f, x0);
      else
          y(1) = 1;
      end
  end

y(3) = min((u - .125*c*(y(1)/M)^2)/sig_u_sn, gbar);

y(2) = E(1) - E(2)*y(1) + y(3)*(u - .125*c*(y(1)/M)^2) ...

         - .5*(Vn(1, 1) + Vn(2, 2)*y(1)^2 - 2*Vn(1, 2)*y(1)) ...
         - .5*(y(3)^2*sig_u_sn + sig_e_sn);

end

[dpb]

Well, you could at least show the error message in context... :(

It means exactly what it says--somewhere you've got an array index that isn't integer-valued or a logical.

The likely candidates are sizecon() and perhaps sizeunc() look like arrays to Matlab instead of (I presume they're supposed to be) functions.

[Image Analyst]

You forgot to include the entire error message - ALL the red text -- you just snipped out a small portion of it for some reason. Failing that you could have attached your m-files, both the calling script and the function. So as it is, I've given up , unless you provide more info.

Answer 1

[Azzi Abdelmalek]

Your function is called y, when you call your function y:

y=y(...)

The variable y will shadow the function y, I recommend to to change the name of your function

[dpb]

Good catch, Azzi...