what is this eror and what does it mean and how can i solve it ?

clear all
x=1 :0.1:10;
f=inline('x-exp(sin(x))');
plot(x.f(x)).grid;

Dot indexing is not supported for variables of this type.

a=1;fa=f(a);
h=10;fb=f(b);
i=0:Nmax-20;c
eps=1.0e-3;
if((fa*fb)<0)
    
    for i=0 :nmax
    x=(a+b)/2;
        i=i+1;
        

it says here that ('loop index 'i' is changed inside of a FOR loop)

          if(sign(f(x))==sign(fa));
           a=x;fa=f(x);
           else
           b=x; fb=f(x);
          end
          fprintf('le nombrre d''iteration i=%d\n',i)
          fprintf('l"intervalle [a,b]=[%f,%f]\n',a,b)
          fprintf('l"intervalle [f(a),f(b)]=[%f,%f]\n',f(a),f(b))
          fprintf('la solution approchée x=%f\n',x)
          plot(x,f(x),'r+');    
    
    end
else disp(ggg)
end

[Matt J]

What is this intended to do?

plot(x.f(x)).grid;

It is not close to any Matlab syntax that I have seen.

[Walter Roberson]

plot(x.f(x)).grid;

looks like Python code.

Answer 1

[Jan]

it says here that ('loop index 'i' is changed inside of a FOR loop)

Yes, and this is the clear explanation already. Do not change the loop counter inside the loop explicitly. This is causing confusions only. Simply omuit the line "i=i+1;"

Avoid the cargo cult programming of "clear all". This is not useful, but removes all loaded functions from the RAM. Reloading them from the slow disk is a waste of time and energy.

Redefining important Matlab functions as variablöes cause unexpected behavior frequently. Here it is "eps". It is a good programming practice, to avoid this.

Inline expressions are outdated for 20 years now. Prefer anonymous functions:

% f=inline('x-exp(sin(x))');
f = @(x) x-exp(sin(x));

Fix this (as Matt J has mentioned already:

plot(x.f(x)).grid;