All files / lib/loss huber.js

100% Statements 63/63
100% Branches 5/5
100% Functions 1/1
100% Lines 63/63

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 643x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 1x 3x 1x 1x 1x 1x 3x 3x 3x 3x 3x 3x  
/**
* @license Apache-2.0
*
* Copyright (c) 2018 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*    http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
 
'use strict';
 
// MODULES //
 
var regularize = require( './../regularize.js' );
 
 
// MAIN //
 
/**
* Given a new observation `(x,y)`, updates the weights using the [Huber loss][1] function.
*
* ## Notes
*
* The Huber loss uses squared-error loss for observations with error smaller than epsilon in magnitude and linear loss above that in order to decrease the influence of outliers on the model fit.
*
* [1]: https://en.wikipedia.org/wiki/Huber_loss
*
* @private
* @param {WeightVector} weights - current model coefficients
* @param {NumericArray} x - feature vector
* @param {number} y - response value
* @param {PositiveNumber} eta - current learning rate
* @param {NonNegativeNumber} lambda - regularization parameter
* @param {PositiveNumber} epsilon - insensitivity parameter
*/
function huberLoss( weights, x, y, eta, lambda, epsilon ) {
	var p = weights.innerProduct( x ) - y;
 
	// Perform L2 regularization...
	regularize( weights, lambda, eta );
 
	if ( p > epsilon ) {
		weights.add( x, -eta );
	} else if ( p < -epsilon ) {
		weights.add( x, +eta );
	} else {
		weights.add( x, -eta * p );
	}
}
 
 
// EXPORTS //
 
module.exports = huberLoss;