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From:  enrique.vidal.sanchez@gmail.com
Newsgroups: comp.soft-sys.matlab
Subject: Found bug in SUM?
Date: Tue, 07 Aug 2007 23:57:25 -0700
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Hi folks,

I wonder why SUM does not work correctly. Please see the examples
below:

OK:
sum([-0.2:0.1:0.1])
 -0.2000

WRONG:
sum([-0.2:0.1:0.2])
-2.7756e-017

OK:
sum([-0.3:0.1:0.2])
  -0.3000

WRONG:
sum([-0.3:0.1:0.3])
 -5.5511e-017

It doesn't work correctly with vectors which are symmetric around
zero. Is this a know bug (or &quot;feature&quot;)?

The Matlab version I am currently using is: 6.5.0.180913a (R13)

It is a very annoying behaviour because there are inbuilt functions in
Matlab like MEAN which call SUM and therefore MEAN in this case
doesn't work as intended either.

Any comment on the above?

Regards,
Enrique

__________
Enrique Vidal Sanchez
Ph.D. in EE. (Automation)
www.vidal.dk


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