Why do I get zero?
3 views (last 30 days)
Show older comments
Running 7.10.0 (R2010a) under Windows 7 on an Intel i5 (Lenovo laptop):
K>> TAhi
TAhi = -8.6578e+009
K>> TAlo
TAlo = -8.6578e+009
K>> TAhi/2.0 - TAlo/2.0
ans = 9.5367e-007
K>> (TAhi+TAlo)/2.0 - TAlo
ans = 0
Why do I get 0 when I should get 9.5367e-007 ? I wouldn't image e-007 is anywhere near machine tolerance.
Any help is appreciated!
0 Comments
Accepted Answer
Nirmal Gunaseelan
on 24 Jun 2011
The next highest floating point number representable relative to the current number is probably the issue here. Please read further at EPS documentation page.
0 Comments
More Answers (2)
Fangjun Jiang
on 24 Jun 2011
Maybe you can type in the following command and then do your calculation again to see the difference
format long
0 Comments
David Young
on 24 Jun 2011
(TAhi-TAlo)/TAhi is close to machine precision, and it's this relative size that matters when comparing two almost equal numbers.
0 Comments
See Also
Categories
Find more on Introduction to Installation and Licensing in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!