dygraphs/src-es5/datahandler/default.js

dygraphs is a fast, flexible open source JavaScript charting library.

/**
 * @license
 * Copyright 2013 David Eberlein (david.eberlein@ch.sauter-bc.com)
 * MIT-licensed (http://opensource.org/licenses/MIT)
 */

/**
 * @fileoverview DataHandler default implementation used for simple line charts.
 * @author David Eberlein (david.eberlein@ch.sauter-bc.com)
 */

/*global Dygraph:false */
"use strict";

Object.defineProperty(exports, '__esModule', {
  value: true
});

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { 'default': obj }; }

var _datahandler = require('./datahandler');

var _datahandler2 = _interopRequireDefault(_datahandler);

/**
 * @constructor
 * @extends Dygraph.DataHandler
 */
var DefaultHandler = function DefaultHandler() {};

DefaultHandler.prototype = new _datahandler2['default']();

/** @inheritDoc */
DefaultHandler.prototype.extractSeries = function (rawData, i, options) {
  // TODO(danvk): pre-allocate series here.
  var series = [];
  var logScale = options.get('logscale');
  for (var j = 0; j < rawData.length; j++) {
    var x = rawData[j][0];
    var point = rawData[j][i];
    if (logScale) {
      // On the log scale, points less than zero do not exist.
      // This will create a gap in the chart.
      if (point <= 0) {
        point = null;
      }
    }
    series.push([x, point]);
  }
  return series;
};

/** @inheritDoc */
DefaultHandler.prototype.rollingAverage = function (originalData, rollPeriod, options) {
  rollPeriod = Math.min(rollPeriod, originalData.length);
  var rollingData = [];

  var i, j, y, sum, num_ok;
  // Calculate the rolling average for the first rollPeriod - 1 points
  // where
  // there is not enough data to roll over the full number of points
  if (rollPeriod == 1) {
    return originalData;
  }
  for (i = 0; i < originalData.length; i++) {
    sum = 0;
    num_ok = 0;
    for (j = Math.max(0, i - rollPeriod + 1); j < i + 1; j++) {
      y = originalData[j][1];
      if (y === null || isNaN(y)) continue;
      num_ok++;
      sum += originalData[j][1];
    }
    if (num_ok) {
      rollingData[i] = [originalData[i][0], sum / num_ok];
    } else {
      rollingData[i] = [originalData[i][0], null];
    }
  }

  return rollingData;
};

/** @inheritDoc */
DefaultHandler.prototype.getExtremeYValues = function (series, dateWindow, options) {
  var minY = null,
      maxY = null,
      y;
  var firstIdx = 0,
      lastIdx = series.length - 1;

  for (var j = firstIdx; j <= lastIdx; j++) {
    y = series[j][1];
    if (y === null || isNaN(y)) continue;
    if (maxY === null || y > maxY) {
      maxY = y;
    }
    if (minY === null || y < minY) {
      minY = y;
    }
  }
  return [minY, maxY];
};

exports['default'] = DefaultHandler;
module.exports = exports['default'];