MATLAB: CODE ASSISTANCE

eigen valueequationsfunctionfzero

Hi, I have the following code ,but it gives an error. The code is :
     function lambda = drive_zr17t9(p)
      format short e;
      load saved_data;
      theta = pi/2;
      zeta = cos(theta);
      I = eye(n,n);
      Q = zeta*I-p*p';
      %T is a matrix(5,5)
      Mroot = M.^(1/2);  %optimization

      T = Mroot*Q*Mroot;
      %find the eigen values
      E = eig(T);
      %find the negative eigen values -- this section still needs to be fixed
      ind = find(E<0);
      G = E(ind);
      %find the smallest negative eigen value
      gamma = min(abs(G));  %this is almost certainly wrong!
      %now solve for lambda
      bounds = sort([0, -1/gamma]);  %in case gamma is positive
      Minv = inv(M);  %optimization
      lambda = fzero(@(lambda) zr17t9(lambda,  Minv, Q, zm), bounds);  %do the searching

    end
   function r = zr17t9(lambda, Minv, Q, zm)
      Winv = inv(mInv+lambda.*Q);
      r = -ctranspose(zm)*Minv*Winv*Q*Winv*Minv*zm;
    end
_*The error is :
    ??? Error using ==> fzero
  FZERO cannot continue because user supplied function_handle ==> @(lambda) zr17t9(lambda,  Minv, Q, zm)
  failed with the error below.
Variable 'zm' is used as a command function. 
Error in ==> drive_zr17t901 at 21
    lambda = fzero(@(lambda) zr17t9(lambda,  Minv, Q, zm), bounds);  %do the searching
_*

Best Answer

Remove the final "end" statement from drive_zr17t9 and the code would likely start working.
This is a side effect of "poofing variables into existence" through a load() statement.
Matt's approach is a better one over the long term.
[Addition: code with Matt's suggested changes]
[Code modified to reflect the fact p is in the .mat file after all]
[Code modified: Minv -> M_inv]
    function lambda = drive_zr17t9
      format short e;
      Params = load('saved_data.mat');
      theta = pi/2;
      zeta = cos(theta);
      I = eye(Params.n,Params.n);
      Q = zeta*I-Params.p*Params.p';
      %T is a matrix(5,5)
      Mroot = Params.M.^(1/2);  %optimization

      T = Mroot*Q*Mroot;
      %find the eigen values
      E = eig(T);
      %find the negative eigen values -- this section still needs to be fixed
      ind = find(E<0);
      G = E(ind);
      %find the smallest negative eigen value
      gamma = min(abs(G));  %this is almost certainly wrong!
      %now solve for lambda
      bounds = sort([0, -1/gamma]);  %in case gamma is positive
      M_inv = inv(Params.M);  %optimization
      lambda = fzero(@(lambda) zr17t9(lambda,  M_inv, Q, Params.zm), bounds);  %do the searching
    end
    function r = zr17t9(lambda, M_inv, Q, zm)
      Winv = inv(M_inv+lambda.*Q);
      r = -zm'*M_inv*Winv*Q*Winv*M_inv*zm;
    end
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