MATLAB Answers

Doubt in a product erro

17 views (last 30 days)
Hi, I have wrinting a code e get a 1×0 empty double row vector error
So, what I wrote:
t1 = 0:0.01:300;
pmenor = 25*0.9;
pmaior = 25*(1.1);
idx1 = find(t1== pmenor);
idx2 = find(t1 == pmaior);
I got
idx2 =
1×0 empty double row vector
But, if I write:
idx2 = find(t1 == 27.5);
idx2 =
2751
So I dont understand the error since idx1 gives me the correct answer, because we know that 25*1.1 = 27.5.
Thanks for reading.

Accepted Answer

Sulaymon Eshkabilov
Sulaymon Eshkabilov on 2 Apr 2021
Edited: Sulaymon Eshkabilov on 2 Apr 2021
Here is a small correction to obtain the correct answers in your exercise:
t1 = 0:0.01:300;
N = 2; % Number of decimal digits to be rounded, e.g.: N = 2 or 3 or 5, etc.
pmenor = round(25*0.9, N);
pmaior = round(25*(1.1), N);
idx1 = find(t1== pmenor);
idx2 = find(t1 == pmaior);
  2 Comments
Sulaymon Eshkabilov
Sulaymon Eshkabilov on 4 Apr 2021
You are welcome - it is a pleasure.

Sign in to comment.

More Answers (1)

the cyclist
the cyclist on 2 Apr 2021
The reason has to do with the accuracy of floating-point math on a binary computer. I suggest you read this question and answer, to get a better understanding of what is going on.
  1 Comment
Nélio Dias
Nélio Dias on 4 Apr 2021
Thanks for the sugestion

Sign in to comment.

Products


Release

R2018a

Community Treasure Hunt

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

Start Hunting!

Translated by