How can I store the values for a b mid fa fb fmid at every iteration?

clear;

clc;

%Use (0, 1) as the initial bracketing interval thus:

a = 0;

b = 1;

%Computing the mid point

mid = (a+b)/2;

%Computing the function f(x) = xe^x - cos(x) at point a,b and mid

format long

fa = (a*exp(a)) - (cos(a));

fb = (b*exp(b)) - (cos(b));

fmid = (mid*exp(mid)) - (cos(mid));

%Code For Loop that identifies the sign and assigns variables accordingly

for k=1:6 %Number of Iterations

if sign(fa) ~= sign(fmid)

b=mid;

else

a=mid;

end

%Compute a b mid fa fb fmid

a;

b;

mid = (a+b)/2;

fa = (a*exp(a)) - (cos(a));

fb = (b*exp(b)) - (cos(b));

fmid = (mid*exp(mid)) - (cos(mid));

end

%Display Last Iteration Values

k

a

b

mid

fa

fb

fmid

Answer 1

[Image Analyst]

Not sure what you want to do but you definitely need to add indexes to the array so perhaps it's this:

numberOfIterations = 6;
%Use (0, 1) as the initial bracketing interval thus:
a = zeros(1, numberOfIterations);
b = ones(1, numberOfIterations);
%Computing the mid point
mid = (a + b) / 2;
%Computing the function f(x) = xe^x - cos(x) at point a,b and mid
format long
fa = (a .* exp(a)) - (cos(a));
fb = (b .* exp(b)) - (cos(b));
fmid = (mid .* exp(mid)) - (cos(mid));
%Code For Loop that identifies the sign and assigns variables accordingly
for k = 1 : numberOfIterations % Number of Iterations
    if sign(fa) ~= sign(fmid)
        b(k)=mid(k);
    else
        a(k)=mid(k);
    end
    %Compute a b mid fa fb fmid
    a(k);
    b(k);
    mid(k) = (a(k) + b(k))/2;
    fa(k) = (a(k) * exp(a(k))) - (cos(a(k)));
    fb(k) = (b(k) * exp(b(k))) - (cos(b(k)));
    fmid(k) = (mid(k) * exp(mid(k))) - (cos(mid(k)));
end
%Display Last Iteration Values
k
a
b
mid
fa
fb
fmid

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[Jorge Arturo Clares Pastrana]

Hi,

Im trying to simply store the value of each variable at every iteration.

For Example if im doing 6 iterations save in a matrix the value of a1 a2 a3 a4 a5 a6

[Image Analyst]

Yep, those are all saved in those arrays. Note that each is an array of 6 values - the values from every iteration.

[Torsten]

for k=1:6 %Number of Iterations
    if sign(fa) ~= sign(fmid) 
        b=mid;
    else
        a=mid;
    end
    %Compute a b mid fa fb fmid
    a;
    b;
    mid = (a+b)/2;
    fa = (a*exp(a)) - (cos(a));
    fb = (b*exp(b)) - (cos(b));
    fmid = (mid*exp(mid)) - (cos(mid));
    K(k) = k;
    A(k) = a;
    B(k) = b;
    MID(k) = mid;
    FA(k) = fa;
    FB(k) = fb;
    FMID(k) = fmid;     
end

And initialize the arrays K,A,B,MID,FA,FB,FMID before entering the loop.

[Jorge Arturo Clares Pastrana]

Thankyou!

This helped alot