/*
* Copyright 2016 IBM Corp.
*
* 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.
*/
(function () {
var JavaWrapper = require(EclairJS_Globals.NAMESPACE + '/JavaWrapper');
var Logger = require(EclairJS_Globals.NAMESPACE + '/Logger');
var Utils = require(EclairJS_Globals.NAMESPACE + '/Utils');
var logger = Logger.getLogger("util_StatCounter_js");
/**
* @classdesc
* A class for tracking the statistics of a set of numbers (count, mean and variance) in a
* numerically robust way. Includes support for merging two StatCounters. Based on Welford
* and Chan's [[http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance algorithms]]
* for running variance.
*
* @class
* @memberof module:eclairjs/util
*/
var StatCounter = function (javaObj) {
var jvmObject;
if (javaObj instanceof org.apache.spark.util.StatCounter) {
jvmObject = javaObj;
} else {
jvmObject = new org.apache.spark.util.StatCounter();
}
JavaWrapper.call(this, jvmObject);
};
StatCounter.prototype = Object.create(JavaWrapper.prototype);
StatCounter.prototype.constructor = StatCounter;
/**
* Add a value into this StatCounter, updating the internal statistics.
* @param {float | module:eclairjs/util.StatCounter} value
* @returns {module:eclairjs/util.StatCounter}
*/
StatCounter.prototype.merge = function (value) {
var javaObject = this.getJavaObject().merge(Utils.unwrapObject(value));
return new StatCounter(javaObject);
};
/**
* Clone this StatCounter
* @returns {module:eclairjs/util.StatCounter}
*/
StatCounter.prototype.copy = function () {
var javaObject = this.getJavaObject().copy();
return new StatCounter(javaObject);
};
/**
* @returns {integer}
*/
StatCounter.prototype.count = function () {
return this.getJavaObject().count();
};
/**
* @returns {number}
*/
StatCounter.prototype.mean = function () {
return this.getJavaObject().mean();
};
/**
* @returns {number}
*/
StatCounter.prototype.sum = function () {
return this.getJavaObject().sum();
};
/**
* @returns {number}
*/
StatCounter.prototype.max = function () {
return this.getJavaObject().max();
};
/**
* @returns {number}
*/
StatCounter.prototype.min = function () {
return this.getJavaObject().min();
};
/**
* Return the variance of the values.
* @returns {number}
*/
StatCounter.prototype.variance = function () {
return this.getJavaObject().variance();
};
/**
* Return the sample variance, which corrects for bias in estimating the variance by dividing
* by N-1 instead of N.
* @returns {number}
*/
StatCounter.prototype.sampleVariance = function () {
return this.getJavaObject().sampleVariance();
};
/**
* Return the standard deviation of the values.
* @returns {number}
*/
StatCounter.prototype.stdev = function () {
return this.getJavaObject().stdev();
};
/**
* Return the sample standard deviation of the values, which corrects for bias in estimating the
* variance by dividing by N-1 instead of N.
* @returns {number}
*/
StatCounter.prototype.sampleStdev = function () {
return this.getJavaObject().sampleStdev();
};
/**
* @returns {string}
*/
StatCounter.prototype.toString = function () {
return this.getJavaObject().toString();
};
//
// static methods
//
/**
* Build a StatCounter from a list of values passed as variable-length arguments.
* @param {...number} values
* @returns {module:eclairjs/util.StatCounter}
*/
StatCounter.apply = function (values) {
var javaObject = org.apache.spark.util.StatCounter.apply(values);
return new StatCounter(javaObject);
};
module.exports = StatCounter;
})();