Re: 'Code Wanted: Calculate Pi in PB_DOS' from Source Code Forum

[Thomas Gohel]

Hello Frank,

here's some old PB/DOS code
http://www.pbhq.de/filebase/fdb110.html#CALC-PI.BAS


Best wishes,

Thomas

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[Tom Hanlin]

The LONGPI code for PB/Win can probably be translated...

http://powerbasic.com/files/pub/pbwin/misc/

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Tom Hanlin, PowerBASIC Staff
Opinions expressed may not be those of my employer or myself

[Dave Biggs]

Original question posed in the Source Code forum..

Greetings ...

Would someone please be kind enough to post a simple Pi calculation code using PB-DOS?

Specificly, I desire to see code where variable X equals number of places that Pi is to be carried to - be it 10, 100, 707 or whatever!

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Thanx-A-Lot and Enjoy, Frank -- My PB

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Frank,

Here is some text snipped from PB's docs:

Pi is a transcendental constant, meaning that it has an infinite number of decimal places.
To 15-place accuracy, adequate for most applications, p = 3.141592653589793##.
This value can be closely approximated with the expression:
pi## = 4 * ATN(1)
..
The ATN function always returns an Extended-precision result.
..
Extended-precision values require 10 bytes of storage each.
They have a range of approximately +/- 3.4x10^-4932 to 1.2x10^4932,
and offer 18 digits of precision. All 18 digits can be "displayed" using
the extended STR$ format (eg, STR$(var##,18))

eg.

pi## = 4 * ATN(1)
For X& = 1 to 18
Pi$ = Str$(pi##, x&)
Print Pi$
next

Sorry, I don't know if you can calculate to better than 18 digits of precision using PowerBASIC..

Rgds Dave

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