Displaying non existant array elements

Why am I getting repeating numbers for the array x as an output for the following piece of script?
x=1:0.5:5;
for i=1:length(x);
y(i)=x(i)^2;
end
fprintf(' x y\n')
x y
Results=[x;y];
fprintf('%10.0f %38.16f\n', Results);
1 1.0000000000000000 2 2.2500000000000000 2 4.0000000000000000 2 6.2500000000000000 3 9.0000000000000000 4 12.2500000000000000 4 16.0000000000000000 4 20.2500000000000000 5 25.0000000000000000

1 Comment

“Why am I getting repeating numbers for the array x as an output for the following piece of script?”

You are not getting the same values repeating in x. You just confused how values are displayed with the values stored in memory. Try printing the values of x with e.g. two decimal places. Then tell us what you see.

Sign in to comment.

 Accepted Answer

x=1:0.5:5;
for i=1:length(x);
y(i)=x(i)^2;
end
fprintf(' x y\n')
x y
Results=[x;y];
fprintf('%10.2f %38.2f\n', Results);
1.00 1.00 1.50 2.25 2.00 4.00 2.50 6.25 3.00 9.00 3.50 12.25 4.00 16.00 4.50 20.25 5.00 25.00
Because the '%10.0f' required rounding the x values to display integer values...

2 Comments

Great! Thanks a billion
No problem...as @Stephen23 notes directly and my response says same thing indirectly, you have to remember the difference between what the variable value and its representation may be.
BTW, you do recognize that with MATLAB array syntax you can eliminate the need for the for...end loop in the above, right?
x=1:0.5:5;
y=x.^2;
Results=[x;y];
fprintf('%10s%38s\n','x','y')
x y
fprintf('%10.2f %38.2f\n', Results);
1.00 1.00 1.50 2.25 2.00 4.00 2.50 6.25 3.00 9.00 3.50 12.25 4.00 16.00 4.50 20.25 5.00 25.00
NOTA BENE the "dot operator" on the expnentiation power, .^: to indicate element-wise operations rather than mpower, ^: which is matrix exponentiation..

Sign in to comment.

More Answers (0)

Categories

Products

Release

R2023a

Asked:

on 8 Mar 2025

Edited:

dpb
on 8 Mar 2025

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!