text: import Layer from './base.js'
  
  export default class AbsLayer extends Layer {
  	calc(x) {
  		this._i = x
  		this._o = x.copyMap(Math.abs)
  		return this._o
  	}
  
  	grad(bo) {
  		const bi = this._i.copyMap(v => (v < 0 ? -1 : 1))
  		bi.mult(bo)
  		return bi
  	}
  }
  