From: Robert Klemme <shortcutter@...>
Date: 2010-04-29T05:20:06+09:00
Subject: Re: flt gem for arbitrary precision

On 04/28/2010 11:31 AM, Giampiero Zanchi wrote:
> ciao a tutti (hi to hall)
> 
> I just discoverd a gem to have arbitrary precision numbers and want to
> share with the forum.
> 
> Install the gem with
> 
> gem install flt
> 
> an example script follows; it computes the square root of 2
> 
> require 'flt'
> include Flt
> 
> DecNum.context.precision = 200
> 
> p DecNum(2).sqrt
> 
> produces:
> 
> DecNum('1.4142135623730950488016887242096980785696718753769480731766797379907324784621070388503875343276415727350138462309122970249248360558507372126441214970999358314132226659275055927557999505011527820605715')
> 
> documentation here
> http://flt.rubyforge.org/

What's the difference (precision? performance?) vs. doing

irb(main):001:0> require 'bigdecimal'
=> true
irb(main):002:0> BigDecimal("2").sqrt(200).to_s
=> 
"0.1414213562373095048801688724209698078569671875376948073176679737990732478462107038850387534327641572735013846230912297024924836055850737212644121497099935831413222665927505592755799950501152782060571470109559971605970125E1"
irb(main):003:0> BigDecimal("2").sqrt(200)
=> #<BigDecimal:93215a4,'0.1414213562 3730950488 0168872420 9698078569 
6718753769 4807317667 9737990732 4784621070 3885038753 4327641572 
7350138462 3091229702 4924836055 8507372126 4412149709 9935831413 
2226659275 0559275579 9950501152 7820605714 7010955997 
1605970125E1',224(224)>
irb(main):004:0>

?

Kind regards

	robert

-- 
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