[#68478] Looking for MRI projects for Ruby Google Summer of Code 2015 — Tony Arcieri <bascule@...>

Hi ruby-core,

10 messages 2015/03/10

[ruby-core:68567] [Ruby trunk - Bug #10850] [Rejected] BigDecimal division incorrect

From: shugo@...
Date: 2015-03-20 06:18:15 UTC
List: ruby-core #68567
Issue #10850 has been updated by Shugo Maeda.

Status changed from Open to Rejected

Elyasin Shaladi wrote:
> Thanks for the answer Shugo,
> 
>  however I am not sure if that is easily possible for me in that case. I use BigDecimal as a fiedl type in a Rails application and don't see how I can ues Rational here :-(
> Any suggestions or tips or references? would be very helpful.

You can use BigDecimal#to_r to convert a BigDecimal to a Rational.


----------------------------------------
Bug #10850: BigDecimal division incorrect
https://bugs.ruby-lang.org/issues/10850#change-51882

* Author: Elyasin Shaladi
* Status: Rejected
* Priority: Normal
* Assignee: ruby-core
* ruby -v: ruby 2.2.0p0 (2014-12-25 revision 49005) [x86_64-linux]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN
----------------------------------------
I tried this in Ruby 2.1.4, 2.1.5 and 2.2.0, but in none of the versions it seems correct to me.

irb(main):041:0* amount1 = BigDecimal("241.3")
=> #<BigDecimal:7f49bcb03558,'0.2413E3',18(18)>

irb(main):042:0> amount2 = BigDecimal("1800")
=> #<BigDecimal:7f49bcaf3400,'0.18E4',9(18)>

irb(main):043:0> rate = amount1 / amount2
=> #<BigDecimal:7f49bcae8398,'0.1340555555 5555555555 5555556E0',27(45)>

irb(main):044:0> rate * amount2 #should return amount1 = 241.3 in BigDecimal, but it does not
=> #<BigDecimal:7f49bcad6a30,'0.2413000000 0000000000 00000008E3',36(45)>


My guess is that there is a bug in the BigDecimal implementation.



-- 
https://bugs.ruby-lang.org/

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