MATLAB: Prevent the evaluation of a function

function evaluationoptimization

Hi!
I'm running an optimization code as follows:
[xval,betaval] = fmincon(@betaindex,[1500 23 1800],...              
    [-1 0 0;0 -1 0  ; 0 0 -1],[0; 0; 0],...       
    [],[],[],[],@constraints,options);
The constraint function as follows:
function [c, ceq] = constraints(xval) 
a=MLR();
ceq = a(1)*xval(1)+a(2)*((xval(1))^2)+a(3)*tan(DR(xval(2)))+a(4)*((tan(DR(xval(2))))^2)+a(5)*xval(3)+...
+a(6)*((xval(3))^2)+a(7)*xval(1)*tan(DR(xval(2)))+a(8)*tan(DR(xval(2)))*xval(3)+a(9)*xval(1)*xval(3); 
c=[];
This is running well, but my only problem is how much time is required to run all the program. As this is an iterative procedure, in every iteration the whole @constraint function is evaluated and it takes to much time to get MLR() in every single iteration. Is there any way i can "freeze" the results in the first one and prevent this function from being evaluated in subsequent iterations ?
Thank you very much and sorry for this newbs question!

Best Answer

mlr = MLR();
[xval,betaval] = fmincon(@betaindex, [1500 23 1800], ...              
  [-1 0 0;0 -1 0  ; 0 0 -1], [0; 0; 0], ...       
  [], [], [], [], @(xval) constraints(xval, mlr), options);  
function [c, ceq] = constraints(xval, mlr) 
    a = mlr;
    ceq = a(1)*xval(1) + a(2)*((xval(1))^2) + a(3)*tan(DR(xval(2))) + a(4)*((tan(DR(xval(2))))^2) + a(5)*xval(3) + ...
    + a(6)*((xval(3))^2) + a(7)*xval(1)*tan(DR(xval(2))) + a(8)*tan(DR(xval(2)))*xval(3) + a(9)*xval(1)*xval(3); 
    c = [];
Are you sure you intended the unary "+" before a(6) ? The previous line ends in +... so there is an addition there, making the + at the beginning of the a(6) line into a unary "+"
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