getting error in line 5 please help

functin=@(x) (3*(-1-212*x)^2+(-1-212*x)-4*(4-170*x)-7)^2+(4-170*x-1-212*x2)^2;
ta3ot=0.001;
Up_limit=2;
Low_limit=0;
[min_x,y_min]=golden_cut(functin,ta3ot,Up_limit,Low_limit); %%%%%%%%%%% hereeeeeeeeeeeeeeeeeeeeeeeeeeee

function[min_x,y_min]=golden_cut(functin,ta3ot,Up_limit,Low_limit)
x1=Low_limit+0.381966*(Up_limit-Low_limit);
x2=Low_limit+0.618034*(Up_limit-Low_limit);
    while(sqrt((x2-x1)^2)>ta3ot)
        if(functin(x1)>functin(x2))
        Low_limit=x1;
        x1=x2;
        x2=Low_limit+0.618034*(Up_limit-Low_limit);
        else
        Up_limit=x2;
        x2=x1;
        x1=Low_limit+0.381966*(Up_limit-Low_limit);
        end
    end
min_x=(x1+x2)/2;
y_min=(functin(x1)+functin(x2))/2;
end

Answer 1

[Yongjian Feng]

Use the matlab debugger. It will tell you what error it is.

[mohammad massarwe]

can you tell me what the problem ?

Answer 2

[Sardar Usama]

The error is in line-1.

functin=@(x) (3*(-1-212*x)^2+(-1-212*x)-4*(4-170*x)-7)^2+(4-170*x-1-212*x2)^2;

x2 is undefined in above line.

Answer 3

[Star Strider]

The error refers to ‘x2’ not being defined in ‘functin’:

functin=@(x) (3*(-1-212*x)^2+(-1-212*x)-4*(4-170*x)-7)^2+(4-170*x-1-212*x2)^2;
                                                                         ↑ ← HERE

Since it is not obvious whether this is a simple typographical error or if it supposed to be ‘x*2’ or ‘x^2’ (or perhaps something else), you have to determine what you want, and fix it. With that ambiguity resolved, the code runs without error.

% functin=@(x) (3*(-1-212*x)^2+(-1-212*x)-4*(4-170*x)-7)^2+(4-170*x-1-212*x2)^2;
% ta3ot=0.001;
% Up_limit=2;
% Low_limit=0;
% [min_x,y_min]=golden_cut(functin,ta3ot,Up_limit,Low_limit); %%%%%%%%%%% hereeeeeeeeeeeeeeeeeeeeeeeeeeee

min_x = 0.0081

y_min = 10.1141

% 
% function[min_x,y_min]=golden_cut(functin,ta3ot,Up_limit,Low_limit)
% x1=Low_limit+0.381966*(Up_limit-Low_limit);
% x2=Low_limit+0.618034*(Up_limit-Low_limit);
%     while(sqrt((x2-x1)^2)>ta3ot)
%         if(functin(x1)>functin(x2))
%         Low_limit=x1;
%         x1=x2;
%         x2=Low_limit+0.618034*(Up_limit-Low_limit);
%         else
%         Up_limit=x2;
%         x2=x1;
%         x1=Low_limit+0.381966*(Up_limit-Low_limit);
%         end
%     end
% min_x=(x1+x2)/2;
% y_min=(functin(x1)+functin(x2))/2;
% end

.