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Re: strange "eq" behaviour [message #69862 is a reply to message #69770]

Mon, 15 February 2010 09:21

rogass
Messages: 200
Registered: April 2008

Senior Member

On 15 Feb., 17:18, Spon <christoph.b...@gmail.com> wrote:
> On Feb 15, 3:54 pm, chris <rog...@googlemail.com> wrote:
>
>> Hi David,
>> maxx is the correlation coefficient of some data series. It should be
>> exactly 1 if two data vectors are equal - but it isn't - so now I run
>> into bigger problems with the inbuilt correlate function . Anyway,
>> thanks for your hint.
>
>> CR
>
> Hi David,
>
> 'It should be exactly one' is a tricky statement in floating point
> arithmetic.
> Looks like a good time to trot out this old line again:http://www.dfanning.com/math_tips/sky_is_falling.html
>
> Your specific problem (or something very similar) is dealt with this
> article:http://www.dfanning.com/code_tips/comparearray.html
>
> You might have more success comparing floats using this program:http://www.dfanning.com/programs/floats_equal.pro
>
> Regards,
> Chris

Thank you for enlightening me. MAybe I have to do it in this way:
round(value1*(10^(((pp=precision<lowest_precision_of_both_types)))))
operator round(value1*pp) or I have to use the floats_equal.pro

Thanks and regards

CR

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[Message index]

		strange "eq" behaviour By: rogass on Mon, 15 February 2010 07:27
		Re: strange "eq" behaviour By: rogass on Mon, 15 February 2010 09:21
		Re: strange "eq" behaviour By: Spon on Mon, 15 February 2010 08:18

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