lgxz / pisearch

Go language pi search code

pisearch

Go language Pi search code. Requires a file of the digits of Pi and a suffix array built atop them:

<name>.4.bin -- digits of pi, BCD, packed 2 digits per byte

<name>.4.idx -- a suffix array indexing those digits, stored
                as little-endian uint32s.

I've put a copy of pi1m.4.bin and pi1m.4.idx at:

• http://moo.cmcl.cs.cmu.edu/~dga/pi1m.4.bin
• http://moo.cmcl.cs.cmu.edu/~dga/pi1m.4.idx

if you want to play with them. You will need some kind of file of Pi digits in src/pisearch in order to run the tests.

The search code is in src/pisearch. It's had more thought put into it than the quick hack of a web interface in src/piweb. Use at your own risk. The json exported by piweb is still changing a lot as I work on the javascript/html front-end.

Building

cd pisearch
    export GOPATH=`/bin/pwd`
go install pi       (command-line search interface)
go install piweb    (web-based/json search code)
go install pipack   (utility to pack and unpack BCD)

go test pisearch   (requires a pi file - see pisearch_test.go)

Optionally:

go install pigen    (generate pi using the Chudnovsky algorithm)

pigen depends on an external package that you must install using go get:

go get github.com/cznic/mathutil

Of course, you can also check out the pi search code into a subdirectory of your GOPATH, adjusting things as needed for your setup. To verify that you've got things running, try some commands such as:

pi search 1415
pi count 99999