SCRIPT FILE RUNNING ERROR

When I run the script file, a can not receive any command on Matlab either any error. However the program stars and runs smoothly. Please help.

The code was:

%bisection method
f = inline('x.^3-0.165.*x.^2+3.993*10^-4');
x= -5.5:0.1:5.5;
y=f(x);
plot(x,y)
grid  %from the plot we can see that we have a root between -1 and 1.5 but the height x can not be negative. 
%We know that we have a root between 1 and 2(initial guesses)

a=1;
b=2;
m=(a+b)/2;
while abs(f(m))>1e-8
    if f(a)*f(m)>0;
        a=m;
    else
        b=m;
    end
    m=(a+b)/2;
end
m

Answer 1

[Weird Rando]

I ran your code and your stuck in an infinite loop. The f(m) doesn't changes value. Because the variable m doesn't change after it becomes a 2.

[Merve Koç]

Do you have any suggestion? I think changing the b value could be helpfull

[Weird Rando]

I look into this and found some mistakes. The initial guesses f(a) and f(b) must have opposite signs. And your if statement changed the wrong variable. I also change your while loop to a for loop because f(m) may have positive and negative values. (https://en.wikipedia.org/wiki/Bisection_method)

%bisection method
%f = inline('x.^3-x-2');
f = inline('x.^3-0.165.*x.^2+3.993*10^-4');
x= -5.5:0.1:5.5;
y=f(x);
plot(x,y)
grid  %from the plot we can see that we have a root between -1 and 1.5 but the height x can not be negative. 
%We know that we have a root between 1 and 2(initial guesses)
a=-1; %f(a) must be negative
b=2;  %f(b) must be positive
m=(a+b)/2;
for i = 1:15
    if f(m)<0;
        a=m;
    else
        b=m;
    end
    m=(a+b)/2;

end
m
f(m)

[Weird Rando]

And here is the while loop

%bisection method
%f = inline('x.^3-x-2');
f = inline('x.^3-0.165.*x.^2+3.993*10^-4');
x= -5.5:0.1:5.5;
y=f(x);
plot(x,y)
grid  %from the plot we can see that we have a root between -1 and 1.5 but the height x can not be negative. 
%We know that we have a root between 1 and 2(initial guesses)
a=-1; %f(a) must be negative
b=2;  %f(b) must be positive
m=(a+b)/2;
while abs(f(m)) > 1*10^-8
    if f(m)<0;
        a=m;
    else
        b=m;
    end
    m=(a+b)/2;
end
m
f(m)