# Creating a fourth column of my code

2 views (last 30 days)
Hmm! on 16 Jan 2021
I have the following codes:
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format longg
f= @(x) sin(x);
x0 = 2;
ref = cos(2);
hs = 10.^(-(1:16));
errors = [];
for h = hs
derivative = (f(x0+h) - f(x0-h))/(2*h);
error = abs(ref - derivative);
rate = [error(1); error(2:end)./error(1:end-1)];
errors = [errors error] ;
disp([h derivative error rate])
end
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The bolded line is a fouth column in disp([ . ]) which is supposed to be the entries by dividing two consecutive error respectively i,e., the entries in the third column of disp([ . ]). But what I have is rather the repetition of the third column as the fourth column which I dont want. The more I try fixing it, the more difficulties I face. I really need help which is that the fourth column of disp([ . ]) must be the consecutitive division of entries of the third column. Note that the first entry of the fourth column will be empty, 0 or -, because, there is no entry before the fisrt entry of column three. Thanks in advance!
Your problems weren't caused by that, though. It's just good practice not to shadow native MATLAB functions.

R2020a

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