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felu.js
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/
felu.js
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import Layer from './base.js'
/**
* Fast ELU layer
*/
export default class FastELULayer extends Layer {
/**
* @param {object} config object
* @param {number} [config.alpha] alpha
*/
constructor({ alpha = 1, ...rest }) {
super(rest)
this._alpha = alpha
}
calc(x) {
this._i = x
const o = x.copy()
o.map(v => (v > 0 ? v : this._alpha * (Math.exp(v / Math.log(2)) - 1)))
return o
}
grad(bo) {
this._bo = bo
const bi = bo.copy()
bi.broadcastOperate(
this._i,
(a, b) => a * (b > 0 ? 1 : (this._alpha / Math.log(2)) * Math.exp(b / Math.log(2)))
)
return bi
}
update(optimizer) {
let s = 0
for (let i = 0; i < this._i.length; i++) {
if (this._i.value[i] > 0) {
continue
}
s += this._bo.value[i] * (Math.exp(this._i.value[i] / Math.log(2)) - 1)
}
this._alpha -= optimizer.delta('alpha', s / this._i.length)
}
toObject() {
return {
type: 'felu',
alpha: this._alpha,
}
}
}
FastELULayer.registLayer('felu')