which pi formula is given in the decimal module documentation?

[Albert van der Horst]

In article <00b967e1$0$15623$c3e8da3 at news.astraweb.com>,
Steven D'Aprano  <steve at REMOVE-THIS-cybersource.com.au> wrote:
>Nice work! But I have a question...
>
>On Mon, 21 Dec 2009 20:40:40 +0000, Albert van der Horst wrote:
>
>> def pi4():
>>     ' Calculate pi by a 5th order process, with favorable stop
>>     criterion'
>>     precision = 10e-20
>
>
>Why do you say 10e-20 instead of 1e-19?

No thought went into that.
Note that the error jumps from 1e-5 to 1e-25 between iterations,
so 1e-20 or 1e-19 hardly makes a difference.

>--
>Steven

Groetjes Albert

--
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
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