how to run operation row by row. Ex row(n) divide row(n+1)

clc

clear

syms f(x)

f(x) = exp(-((x).^2));

a =0; % lower limit

b = 1; %upper limit

for j=1:6

n = 2.^j;

h = (b-a)/n;

kamir = vpa(int(f,x,a,b));

s = 0.5*(f(a)+f(b));

for i=1:n-1

s = s+f(a+i*h);

end

I =vpa(h*s);

fprintf(' \t %6d \t %f.4 \n ',n,I)

end

Above is my code. after run, we will get 2 column...

for the second column...what I want to do is...I want to compute row(n)/row(n+1)

Hopefully dear all professor/Dr/expert can help me with this problem..thank you in advance

Answer 1

[DUY Nguyen]

Hi, in this modified code, I added a prev_I variable to store the previous value of I. After computing I, we compute the ratio as I / prev_I and print it in the third column!

clear
syms f(x)
prev_I=1;
f(x) = exp(-((x).^2));

a =0;       % lower limit

b = 1;      %upper limit

fprintf('n\t\tIntegral\tRatio\n');

n		Integral	Ratio

for j= 1:6
    
    n = 2.^j;   
    h = (b-a)/n;
    kamir = vpa(int(f,x,a,b));
    s = 0.5*(f(a)+f(b));
    for i=1:n-1
        s = s+f(a+i*h);
    end
    
    I =vpa(h*s); 
    if i==1
        ratio =1;
    else
        ratio = I / prev_I;
    end
    
    
    fprintf('%d\t\t%.4f\t\t%.4f\n', n, I, ratio)
    prev_I = I;
end

2		0.7314		1.0000
4		0.7430		1.0159
8		0.7459		1.0039
16		0.7466		1.0010
32		0.7468		1.0002
64		0.7468		1.0001

[Noriham B]

n Integral Ratio

2 0.7314

4 0.743 0.984387618

8 0.7459 0.996112079

16 0.7466 0.999062416

32 0.7468 0.999732191

64 0.7468 1

Tq so much sir for your help. This is the answer compute using excel, the 1st row of the second column should be empty.

[Noriham B]

its working actually..juz that

should be

else

ratio = prev_I/I ;

the rest is ok...tq so much sir for helping me...

now its working..may God bless u

[DUY Nguyen]

Oh, yes! I see.

No problem :)