candle/candle-nn/src/sampling.rs

21 lines
641 B
Rust

use candle::{Result, Tensor};
/// Sample according to the Gumbel-Softmax distribution.
pub fn gumbel_softmax<D: candle::shape::Dim>(
logits: &Tensor,
temperature: f64,
dim: D,
) -> Result<Tensor> {
if temperature <= 0.0 {
logits.argmax(dim)
} else if temperature == 1.0 {
let minus_g = logits.rand_like(1e-7, 0.999)?.log()?.neg()?.log()?;
let sampled = (logits - minus_g)?.argmax(dim)?;
Ok(sampled)
} else {
let minus_g = logits.rand_like(1e-7, 0.999)?.log()?.neg()?.log()?;
let sampled = (logits + minus_g * (-temperature))?.argmax(dim)?;
Ok(sampled)
}
}