# gammatest
## Definition
[gammatest](https://github.com/SaadDAHMANI/gammatest) is a simple [rust](https://github.com/rust-lang/rust) implementation of the Gamma Test.
Gamma Test [1] is non-parametric test for feature selection frequently used in machine learning.
The [gammatest](https://github.com/SaadDAHMANI/gammatest) crate is based on [the paper](https://ijssst.info/Vol-06/No-1&2/Kemp.pdf) [2].
### References
[1] Stefánsson, A., Končar, N., & Jones, A. J. (1997). A note on the gamma test. Neural Computing & Applications, 5(3), 131-133.
[2] Kemp, S. E., Wilson, I. D., & Ware, J. A. (2004). A tutorial on the gamma test. International Journal of Simulation: Systems, Science and Technology, 6(1-2), 67-75.
## Example
```rust
use gammatest::*;
fn main()
{
// Give the input matrix
let inputs =[
[3.0f32, 4.0, 4.0].to_vec(),
[2.0f32, 1.0, 3.0].to_vec(),
[1.0f32, 0.0, 1.0].to_vec(),
[1.0f32, 1.0, 1.0].to_vec(),
];
// Give the output vector
let output = [54.0f32, 30.0, 3.0, 28.0];
// p is the number of neighbors
let p : usize = 3;
// Build the GammaTest using f32 data type
let mut gt : GammaTest<f32> = GammaTest::new(&inputs, &output, p);
// To use f64 data type
//let mut gt : GammaTest<f64> = GammaTest::new(&inputs, &output, p);
// Call function compute() to compute GammaTest parameters.
gt.compute();
// Check results
assert_eq!(gt.slope, Some(33.54095));
assert_eq!(gt.intercept, Some(20.578278));
}
```
## Current development state
In the current version, [gammatest](https://github.com/SaadDAHMANI/gammatest) uses the "Brute force approach" to sort k-near neighbors, which is a simple but slow method comparing to some others.