MATLAB: Fminunc is not working in the equation, can you help me with these errors? i am a beginner in matlab

fminunc

hi.. i am trying to optimize this equation through matlab's fminunc

in the editor i typed:

function F = fun(x,e) F = -0.2662*x.^6 + 48.19*x.^5 – 3424.2*x.^4 + 121708*x.^3 – 2*e^6*x.^2 + 2*e.^7*x – 6*e.^7; end

in the command line i typed the following and at the same time got results shown:

x0= [0,0]; [x, fval] = fminunc (@fun,x0); ??? Undefined function or variable 'e'.

Error in ==> fun at 2 F = -0.2662*x.^6 + 48.19*x.^5 – 3424.2*x.^4 + 121708*x.^3 – 2*e^6*x.^2 + 2*e.^7*x – 6*e.^7;

Error in ==> fminunc at 227 f = feval(funfcn{3},x,varargin{:});

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

can you help me fix this?

Best Answer

what are your variables in the function? x can be a vector and when plugged in F should evaluate to a scalar. By the looks of your function 'fun' that doesn't seem to be the case.

Related Solutions

MATLAB: Fminunc stopped because it exceeded the function evaluation limit, options.MaxFunEvals = 100 (the default value).

Define the objective function by setting its output with the opposite sign as follows:

function F=fun(x)

F=-0.2662*x.^6+48.19*x.^5-3424.2*x.^4+121708*x.^3-2*exp(6)*x.^2+2*exp(7)*x-6*exp(7);

F=-F;

end

The initial function that you presented does not have a finite global minimum, it tends to -inf due to the negative sign at the coefficient of x^6. The above function has a global minimum, so if you execute the code:

x0 = 1;

[x, fval] = fminunc (@fun,x0)

then the algorithm finds the local minimum of -fun, therefore the global maximum of fun.

MATLAB: I get matlab error :Failure in initial user-supplied objective function evaluation. FMINCON cannot continue.

1. Input vector for the objective function F is only x, not x and xdata.
2. I don't see that you define "xdata".
3. Since I suspect that "xdata" will be a vector, take care that F returns a scalar. As it stands, F returns a vector.

Best wishes

Torsten.

Best Answer

Related Solutions

MATLAB: Fminunc stopped because it exceeded the function evaluation limit, options.MaxFunEvals = 100 (the default value).

MATLAB: I get matlab error :Failure in initial user-supplied objective function evaluation. FMINCON cannot continue.

Related Question