#[macro_use]
extern crate aegir;
extern crate rand;
use aegir::{
ids::{W, X, Y},
Differentiable,
Function,
Identifier,
Node,
ops,
};
use rand::{rngs::SmallRng, Rng, SeedableRng};
const N: usize = 5;
ctx_type!(Ctx { x: X, y: Y, w: W });
fn main() {
let mut rng = SmallRng::seed_from_u64(1994);
let mut ctx = Ctx {
x: [1.0; N],
y: 0.0,
w: [0.0; N],
};
let true_weights: [f64; N] = rng.gen();
let x = X.into_var();
let y = Y.into_var();
let w = W.into_var();
let model = x.dot(w).sigmoid();
let likelihood = model.mul(y).add(ops::OneSub(model).mul(ops::OneSub(y))).ln();
let adj = likelihood.adjoint(W);
for _ in 0..1_000_000 {
ctx.x = rng.gen();
let yy = ctx.x.iter().zip(true_weights.iter()).map(|(x, tw)| x * tw).sum();
ctx.y = rng.gen_bool(ops::sigmoid(yy)) as u8 as f64;
let g: [f64; N] = adj.evaluate(&ctx).unwrap();
for i in 0..N {
ctx.w[i] += 0.0005 * g[i];
}
}
println!("Target: {:?}", true_weights.to_vec());
println!("Solution: {:?}", ctx.w.to_vec());
}