rustframe/examples/logistic_regression.rs

101 lines
3.2 KiB
Rust

use rustframe::compute::models::logreg::LogReg;
use rustframe::matrix::Matrix;
/// Two binary classification demos using logistic regression.
///
/// Example 1 predicts exam success from hours studied.
/// Example 2 predicts whether an online shopper will make a purchase.
fn main() {
student_passing_example();
println!("\n-----\n");
purchase_prediction_example();
}
fn student_passing_example() {
println!("Example 1: exam pass prediction");
// Hours studied for each student
let hours = vec![1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0];
// Label: 0 denotes failure and 1 denotes success
let passed = vec![0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0, 1.0];
let x = Matrix::from_vec(hours.clone(), hours.len(), 1);
let y = Matrix::from_vec(passed.clone(), passed.len(), 1);
let mut model = LogReg::new(1);
model.fit(&x, &y, 0.1, 10000);
let preds = model.predict(&x);
println!("Hours -> pred | actual");
for i in 0..x.rows() {
println!(
"{:>2} -> {} | {}",
hours[i] as i32,
preds[(i, 0)] as i32,
passed[i] as i32
);
}
// Probability estimate for a new student
let new_student = Matrix::from_vec(vec![5.5], 1, 1);
let p = model.predict_proba(&new_student);
println!("Probability of passing with 5.5h study: {:.2}", p[(0, 0)]);
}
fn purchase_prediction_example() {
println!("Example 2: purchase likelihood");
// minutes on site, pages viewed -> made a purchase?
let raw_x = vec![1.0, 2.0, 3.0, 1.0, 2.0, 4.0, 5.0, 5.0, 3.5, 2.0, 6.0, 6.0];
let bought = vec![0.0, 0.0, 0.0, 1.0, 0.0, 1.0];
let x = Matrix::from_rows_vec(raw_x, 6, 2);
let y = Matrix::from_vec(bought.clone(), bought.len(), 1);
let mut model = LogReg::new(2);
model.fit(&x, &y, 0.05, 20000);
let preds = model.predict(&x);
println!("time, pages -> pred | actual");
for i in 0..x.rows() {
println!(
"{:>4}m, {:>2} -> {} | {}",
x[(i, 0)],
x[(i, 1)] as i32,
preds[(i, 0)] as i32,
bought[i] as i32
);
}
let new_visit = Matrix::from_rows_vec(vec![4.0, 4.0], 1, 2);
let p = model.predict_proba(&new_visit);
println!("Prob of purchase for 4min/4pages: {:.2}", p[(0, 0)]);
}
#[test]
fn test_student_passing_example() {
let hours = vec![1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0];
let passed = vec![0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0, 1.0];
let x = Matrix::from_vec(hours.clone(), hours.len(), 1);
let y = Matrix::from_vec(passed.clone(), passed.len(), 1);
let mut model = LogReg::new(1);
model.fit(&x, &y, 0.1, 10000);
let preds = model.predict(&x);
for i in 0..y.rows() {
assert_eq!(preds[(i, 0)], passed[i]);
}
}
#[test]
fn test_purchase_prediction_example() {
let raw_x = vec![1.0, 2.0, 3.0, 1.0, 2.0, 4.0, 5.0, 5.0, 3.5, 2.0, 6.0, 6.0];
let bought = vec![0.0, 0.0, 0.0, 1.0, 0.0, 1.0];
let x = Matrix::from_rows_vec(raw_x, 6, 2);
let y = Matrix::from_vec(bought.clone(), bought.len(), 1);
let mut model = LogReg::new(2);
model.fit(&x, &y, 0.05, 20000);
let preds = model.predict(&x);
for i in 0..y.rows() {
assert_eq!(preds[(i, 0)], bought[i]);
}
}