Not enough input arguments Error

Hello,

I am not that experienced with Matlab errors and was wondering if anyone could help me with why I keep getting this error:

Error using MaxFunctionProblem (line 73)
Not enough input arguments.

Error in fmincon (line 601)
      initVals.f = feval(funfcn{3},X,varargin{:});

Error in MaxFunExe (line 25)
[P,W,U,Wprime,Uprime,fval] =
fmincon(@MaxFunctionProblem,x0,[],[],[],[],[],[],@confun,options);

Caused by:
    Failure in initial user-supplied objective function evaluation. FMINCON
    cannot continue.

Below is my complete program including the functions:

function E = MaxFunctionProblem(P,W,U,Wprime,Uprime)

% Function Formulations
% Multiobjective function

D1 = 0.2;
 a = 2;
 b = 0.2;
 d = 0.1;
 e = 2;
 k = 1;
 P1 = 1;
 P2 = 6;
 W1 = 1;
 W2 = 5;
 U1 = 1;
 U2 = 6;
 W3 = 10;
  L = 10; 
 a2 = 0.01;
 b2 = 0.005;
 i = 1;
 g = 0.1;
 t = 0;
 r = mvnrnd (0,6);
 Theta0 = .005;
 Theta1 = .01;
 Theta2 = .01; 
 Theta3 = .02;

   Inf = 50;

% Expected Unit Profit
% Unknown variables: P,W,U, Uprime, Unit Price

Pprime = 0.2;
v = (0.1*Pprime);

% Expected Unit Production Costs 
 Ltr = Theta0+(Theta1*r)+(Theta2+(Theta3*r))*t;

   FuncEct = @(t,L)(a2 + (b2/(Ltr^i)))*(1-(g*(t)));

   ECTf = integral(FuncEct,t,L);

   % ECTf = @ExpUnitProdCost;

%%%%%%Expected Unit Profit %%%%%%

% q = integral(fun,xmin,xmax) example
% q = integral(fun,xmin,xmax,Name,Value)

   %FuncEct = @(t,L)(a2 + (b1/(Ltr^i)))*(1-(g*t));
   %ExpUnitProdCostX = integral(ECTf,t,L);

   Lfun = @(t,r)Theta0+(Theta1*r)+((Theta2+(Theta3*r)).*t);
   L1 = integral2(Lfun,t,W,r,(U/W));
   L2 = integral2(Lfun,t,(U/r),(U/W),Inf);

   Cs = 0.05*P;

   ExpUnitWarCost = Cs*(L1 + L2);

   ExpUnitProfit = (P + v) - ECTf - ExpUnitWarCost;

%%%%%%Expected increase in market share %%%%%%

Pprime = .2; 
D = D1/((P1^(-a))*((W2 + k)^b)*U2^d);
Q = (D*(P^(-a))*((W + k)^b)*(U^d));
Qprime = (D*(P^(-a))*((Wprime + k)^b)*(((Uprime)^d)*((1 + v)^(-e))));

ExpIncMarketShare = (Pprime*Qprime) + ((1 - Pprime))*Q - Q;

%%%%%%Unit Price %%%%%

UnitPrice = P; 

%%%%%%Market share without extension of warranty %%%%%%

MarShareWOExtWar = Q;

E = -(ExpUnitProfit*ExpIncMarketShare)/(UnitPrice*MarShareWOExtWar);

function [c, ceq] = confun(P,W,U,Wprime,Uprime)

   P1 = 1;
   P2 = 6;
   W1 = 1;
   W2 = 5;
   U1 = 1;
   U2 = 6;
   W3 = 10;
   U3 = 12;

c = [-P + P1;
      P - P2;
     -W + W1;
      W - W2;
     -U + U1;
      U - U2;
     -Wprime + W
      Wprime - W3
     -Uprime + U
      Uprime - U3];
ceq = [];

x0 = [3,4,4,2,2]; 
options = optimset('Algorithm','active-set');
[P,W,U,Wprime,Uprime,fval] = fmincon(@MaxFunctionProblem,x0,[],[],[],[],[],[],@confun,options);

I am trying to find the minimization for 5 unknown variables using 5 constraints. Since this is kind of a complicated problem, i am sort of lost now. Any help would be greatly appreciated. Thanks :)

Answer 1

[Alan Weiss]

I wonder if you understand what type of arguments fmincon is expecting. The quantities you want to optimize should be in a single vector, usually called x. So if you want to find values of P, W, U, Wprime, and Uprime, you should write your objective and constraint functions to take a vector x, and then say things like

 function E = MaxFunctionProblem(x)
 P = x(1);
 W = x(2);
 U = x(3);
 ...

 function [c, ceq] = confun(x)
 P = x(1);
 W = x(2);
 U = x(3);
 ...

etc.

Also, I wonder about your statement Inf = 50. I believe you should not override MATLAB's value.

Alan Weiss

MATLAB mathematical toolbox documentation

[Kam Selley]

Thanks a lot for the clarification! That definitely helped. I did change the inf bound.