= 3.14...

Search 2,000,000,000 decimal digits of Pi, E, the Square Root of 2 and 500M digits of Phi (the Golden Ratio) for the first occurrence of a numeric string, or return 100 digits beginning from the specified starting position (excluding the first whole number digit).

Enter Search Digits or Starting Position:
Mode: Search
Display Digits
Constant: Pi
E
Sqr Root 2
Phi (500M)

Message:



Please enter a numeric string to search or a starting digit (no decimals or commas)



2 billion decimal digits of Pi, E, the Square Root of 2 and 500 million digits of Phi calculated with PiFast43.

About the Irrational Numbers Search Engine:

The Irrational Numbers Search Engine was originally created in 2002 as a demonstration project for fun and as a learning tool for ASP programming. The original implementation offered PI digits, with digits for e, Phi and the Square Root of 2 added in 2011 by popular request. Usage of the search engine has steadily increased over time, with a total of 384,022 queries in the three year period between 2010 & 2012.

Search History Search Types
Search Totals Searches by Type

Over the three year period, 12,428 unique visitors from 111 countries accessed the search engine, including numerous corporations, universities and schools across the globe. I am not entirely sure what sort of research is going on, but it is interesting to see the wide variety of traffic accessing the site.

Search Locations Search Locations
Top Countries Searches by Continent

Searches during this period averaged 7.3 digits, with an average search time of 1.53 seconds. CPU time totaled 587,894 seconds, or over 163 hours!

The search engine was originally implemented as a VB6 executable called by an ASP page, using text files for input and output. That approach was a bit of a kludge, so I ported it to a VB6 class (.dll), which is called as an object. You can download the VB6 source code and executables here. The source code package was downloaded 901 times as of 12/31/2012.

The server hosts one text file for each constant containing the digits to the right of the decimal point. Full scans of the files take less than 20 seconds and searches of the same file run about 25% faster due to disk I/O caching. The application runs on a Windows Server virtual machine allocated 8GB of memory which is hosted on a 2011 Mac Mini Server with a quad core i7 CPU @ 2GHz. An SSD is used, which is essential for maximum throughput.

Send me a note about how you're using the search engine, as well as any comments, suggestions or ideas, such as implementing a faster search method (eg. BCD compression!) using the contact us link at the bottom of the page.

Links:

Pi, e, the Square Root of 2 and the Golden Ratio (Phi) on Wikipedia

10,000 decimal digits of Pi, E, SqrRt2 and Phi

PiFast written by Xavier Gourdon.

The *original* Pi Search Engine that inspired this one; much faster, but only 200m digits. Good background and statistical info.


The search engine has processed 505,361 queries since 01/09/2002

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