# Assert\_equal problem

**URL:** <https://www.ruby-forum.com/t/assert-equal-problem/127971>\
**Category:** Ruby\
**Created:** [February 3, 2008, 3:35pm UTC](https://www.ruby-forum.com/t/assert-equal-problem/127971 "2008-02-03T15:35:59Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Ranieri\_T](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/43a26b/32.png) [@Ranieri\_T](https://www.ruby-forum.com/u/Ranieri_T)\
**Post date:** [February 3, 2008, 3:35pm UTC](https://www.ruby-forum.com/t/assert-equal-problem/127971/1 "2008-02-03T15:35:59Z")

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One of my tests with assert\_equal has the message:

\<5.0e-006\> expected but was  
\<5.0e-006\>.

What seems to be this error?

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**Author:** ![Ranieri\_T](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/43a26b/32.png) [@Ranieri\_T](https://www.ruby-forum.com/u/Ranieri_T)\
**Post date:** [February 3, 2008, 4:06pm UTC](https://www.ruby-forum.com/t/assert-equal-problem/127971/2 "2008-02-03T16:06:01Z")

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On Feb 3, 9:35 am, Ranieri T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> Pará (UFPA)[http://rubytags.blogspot.com/](http://rubytags.blogspot.com/)  
> Can you post some of the code around this test? Chances are you are  
> testing for equality with real numbers and it’s rare that they will  
> ever be exactly equal. A similar situation arises with testing time.  
> The time object is stored internally in milliseconds, but visually it  
> is displayed in seconds. This results in failed tests with:

\<10:01 AM Sun Feb 3 2008\> expected but was  
\<10:01 AM Sub Fep 3 2008\>.

The solution is to use a delta time to be used as a margin of error.

time\_delta = 100  
assert\_in\_delta time1, time2, time\_delta

I used time as an example, but should work for any real numbers

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**Author:** ![Ranieri\_T](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/43a26b/32.png) [@Ranieri\_T](https://www.ruby-forum.com/u/Ranieri_T)\
**Post date:** [February 3, 2008, 9:25pm UTC](https://www.ruby-forum.com/t/assert-equal-problem/127971/3 "2008-02-03T21:25:46Z")

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Ranieri T. wrote:

> One of my tests with assert\_equal has the message:  
> \<5.0e-006\> expected but was  
> \<5.0e-006\>.  
> What seems to be this error?

Read this and you’ll understand.  
“What Every Computer Scientist Should Know About Floating-Point”  
[http://docs.sun.com/source/806-3568/ncg\_goldberg.html](http://docs.sun.com/source/806-3568/ncg_goldberg.html)

Clifford H…

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**Author:** ![Ranieri\_T](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/43a26b/32.png) [@Ranieri\_T](https://www.ruby-forum.com/u/Ranieri_T)\
**Post date:** [February 4, 2008, 11:19pm UTC](https://www.ruby-forum.com/t/assert-equal-problem/127971/4 "2008-02-04T23:19:01Z")

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Thanks for the help.