Calculating Pi

This repository contains PHP source codes for the π (Pi) calculation that has been mentioned with the precision of 201 digits on my web page http://petrfaltus.net/petr-faltus-ludolfovo-cislo-vypocet-pi-na-201-desetinnych-mist.php (czech language only).

There are three polynoms for the π (Pi) calculation implemented here. Polynoms number 2 and 3 (classes tPi2.php and tPi3.php) calculate quick and are very usefull. The polynom number 1 (class tPi1.php) is approaching the π very slow, for example few minutes for the precision of 6 digits. This is the reason, why the calculation using the polynom 1 is commented in do.php file.

The version of PHP

The original version in May 2012 was 5.2.10 (cli). The current version now in February 2020 (at the time of the transfer to this GitHub repository) is 7.3.10 (cli). I also successfully tested PHP versions 5.3.28 (cli) and 5.4.45 (cli).

For these π (Pi) calculations there is the enabled PHP BCMath extension required. It means for example to uncomment the line extension=bcmath in the main [PHP] section of php.ini file.

Cloning to your computer

• install GIT and PHP on your computer
• clone this repository to your computer by the GIT command git clone https://github.com/petrfaltus/php-calculating-pi.git

Running under Linux

• the main do.php expect the path of the php executable /usr/bin/php. If you have installed the php executable to any other directory, please check it by commands whereis php or which php and modify the first row of do.php file
• make sure that the main do.php file is executable. If not, please correct it for example by the linux command chmod +x do.php
• run the main do.php file by the linux command ./do.php

Running under Windows

• copy the do.php file to any other file, for example to main.php
• remove the first row #!/usr/bin/php from the main.php file
• run the main main.php file by the command php main.php