https://github.com/banzaiman/jni-gamma

A simple JNI example to get gamma function values
https://github.com/banzaiman/jni-gamma

Last synced: 9 days ago
JSON representation

A simple JNI example to get gamma function values

• Host: GitHub
• URL: https://github.com/banzaiman/jni-gamma
• Owner: BanzaiMan
• Created: 2011-11-10T14:51:20.000Z (about 13 years ago)
• Default Branch: master
• Last Pushed: 2011-11-13T01:15:22.000Z (about 13 years ago)
• Last Synced: 2024-11-08T09:51:22.513Z (2 months ago)
• Language: Ruby
• Homepage:
• Size: 93.8 KB
• Stars: 1
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.txt

Awesome Lists containing this project

README

        
This is a simple example of the use of JNI. This shows how Java can call

the native function tgamma() to get the Gamma function value.

To use:

1. Generate Example.h:

  javah Example.java

2. Generate shared object from gamma.c. For example (on a Mac):

  cc -shared gamma.c -o libgamma.dylib \

    -I /Library/Java/JavaVirtualMachines/1.6.0_29-b11-397.jdk/Contents/Headers/

3. Compile Example.java:

  javac Example.java

4. Execute!

  java Example

Note: if you want to be sure that tgamma() is returning a reasonable

value, try tgamma(5.0) = 4! = 24, tgamma(0.5)**2 = Math.Pi()

For comparison, we do the same with (J)Ruby, using FFI. For MRI, you

would need to require 'rubygems' as well.

Note: In Ruby 1.9, the gamma function is available as 'Math::gamma'.

bench_gamma.rb compares the performance of 3 methods. Be sure to run it

in the 1.9 mode.