Error using ^ One argument must be a square matrix and the other must be a scalar. Use POWER (.^) for elementwise power.

Hi, I'm Trying to write minimization function from this function,

(4-2.1*x1^2+x1^4/3)*x1^2+x1*x2+(-4+4*x2^2)*x2^2

where,

   -10 <= x1 <= 10 and -10 <= x2 <= 10.

this what I'm writing, is this right?

min = -10;
max = 10;
x1 = min+max*rand();
x2 = min+max*rand();

T = 1.0;
Tmin = 0.0000001;
refresh = 0.9;

finalMin = (4-2.1*x1^2+x1^4/3)*x1^2+x1*x2+(-4+4*x2^2)*x2^2;
finalCoordinate=[x1,x2];

while(T>Tmin)
    i=0;
    while(i<=300)
        x1= min+max*rand(1,1);
        x2= min+max*rand(1,1);
        newMin = (4-2.1*x1^2+x1^4/3)*x1^2+x1*x2+(-4+4*x2^2)*x2^2;
    delta1 = finalMin-newMin;
        if(newMin < finalMin)
            finalMin=newMin;
            finalCoordinate=[x1,x2];
    elseif(2.71828^(delta/T))>(0+(rand(1)*1))
            finalCoordinate=[x1,x2];
        end;
        i=i+1;
    end;
    T = T*refresh;
end;

But why, at

elseif(2.71828^(delta/T))>(0+(rand(1)*1))

Error using ^ One argument must be a square matrix and the other must be a scalar. Use POWER (.^) for elementwise power.

And how to obtain 100% accuracy from that coordinate?

Answer 1

[Walter Roberson]

Your code does not define delta so you are getting whatever value happened to be laying around, which happened to be a vector or array.

Note: use exp(x) instead of 2.718^(x)