ERROR: FMINCON requires all values returned by functions to be of data type double.

This is the main running code, once started will always report this error.

Func is my object function.

Func =  @(x) WW_Period_Sum(x);

options = optimoptions('fmincon','Display','iter');

nonlcon = [];%@myConstraintFunction;

a = fmincon(Func, x0, [], [], [], [], [], [], nonlcon, options);%x0 is already assigned.

Unrecognized function or variable 'x0'.

I have this nonlcon function. ce and ceq are all array of cells about x

function [ce, ceq] = myConstraintFunction(x)
    ce = @(x) ineq_temp;
    
    ceq = @(x) eq_temp; 
end

H is a matrix, and I'm trying to find its Condition Number.

function cond_value = calcCond(x,t);
    cond_value = @(x,t) cond(H);
end

Sum of all values within 0.01s.

function WW_period = WW_Period_Sum (x);
    WW_period_=@(x) 0;
    for t=0:0.002:0.01
        cond_temp = @(x) calcCond(x, t);
        WW_period_ = @(x) WW_period_(x) + cond_temp(x);
    end
    WW_period = WW_period_;
end

And Keep reporting errors "Error using fmincon (line 19)

FMINCON requires all values returned by functions to be of data type double."

Thanks for giving me a lift to the station.!!!

Answer 1

[Walter Roberson]

WW_period_=@(x) 0;

You are returning a function handle. You need to return a scalar numeric value instead.