/**
|
* jqPlot
|
* Pure JavaScript plotting plugin using jQuery
|
*
|
* Version: 1.0.8
|
* Revision: 1250
|
*
|
* Copyright (c) 2009-2013 Chris Leonello
|
* jqPlot is currently available for use in all personal or commercial projects
|
* under both the MIT (http://www.opensource.org/licenses/mit-license.php) and GPL
|
* version 2.0 (http://www.gnu.org/licenses/gpl-2.0.html) licenses. This means that you can
|
* choose the license that best suits your project and use it accordingly.
|
*
|
* Although not required, the author would appreciate an email letting him
|
* know of any substantial use of jqPlot. You can reach the author at:
|
* chris at jqplot dot com or see http://www.jqplot.com/info.php .
|
*
|
* If you are feeling kind and generous, consider supporting the project by
|
* making a donation at: http://www.jqplot.com/donate.php .
|
*
|
* sprintf functions contained in jqplot.sprintf.js by Ash Searle:
|
*
|
* version 2007.04.27
|
* author Ash Searle
|
* http://hexmen.com/blog/2007/03/printf-sprintf/
|
* http://hexmen.com/js/sprintf.js
|
* The author (Ash Searle) has placed this code in the public domain:
|
* "This code is unrestricted: you are free to use it however you like."
|
*
|
*/
|
(function($) {
|
|
/**
|
* Class: $.jqplot.Trendline
|
* Plugin which will automatically compute and draw trendlines for plotted data.
|
*/
|
$.jqplot.Trendline = function() {
|
// Group: Properties
|
|
// prop: show
|
// Wether or not to show the trend line.
|
this.show = $.jqplot.config.enablePlugins;
|
// prop: color
|
// CSS color spec for the trend line.
|
// By default this wil be the same color as the primary line.
|
this.color = '#666666';
|
// prop: renderer
|
// Renderer to use to draw the trend line.
|
// The data series that is plotted may not be rendered as a line.
|
// Therefore, we use our own line renderer here to draw a trend line.
|
this.renderer = new $.jqplot.LineRenderer();
|
// prop: rendererOptions
|
// Options to pass to the line renderer.
|
// By default, markers are not shown on trend lines.
|
this.rendererOptions = {marker:{show:false}};
|
// prop: label
|
// Label for the trend line to use in the legend.
|
this.label = '';
|
// prop: type
|
// Either 'exponential', 'exp', or 'linear'.
|
this.type = 'linear';
|
// prop: shadow
|
// true or false, whether or not to show the shadow.
|
this.shadow = true;
|
// prop: markerRenderer
|
// Renderer to use to draw markers on the line.
|
// I think this is wrong.
|
this.markerRenderer = {show:false};
|
// prop: lineWidth
|
// Width of the trend line.
|
this.lineWidth = 1.5;
|
// prop: shadowAngle
|
// Angle of the shadow on the trend line.
|
this.shadowAngle = 45;
|
// prop: shadowOffset
|
// pixel offset for each stroke of the shadow.
|
this.shadowOffset = 1.0;
|
// prop: shadowAlpha
|
// Alpha transparency of the shadow.
|
this.shadowAlpha = 0.07;
|
// prop: shadowDepth
|
// number of strokes to make of the shadow.
|
this.shadowDepth = 3;
|
this.isTrendline = true;
|
|
};
|
|
$.jqplot.postSeriesInitHooks.push(parseTrendLineOptions);
|
$.jqplot.postDrawSeriesHooks.push(drawTrendline);
|
$.jqplot.addLegendRowHooks.push(addTrendlineLegend);
|
|
// called witin scope of the legend object
|
// current series passed in
|
// must return null or an object {label:label, color:color}
|
function addTrendlineLegend(series) {
|
var ret = null;
|
if (series.trendline && series.trendline.show) {
|
var lt = series.trendline.label.toString();
|
if (lt) {
|
ret = {label:lt, color:series.trendline.color};
|
}
|
}
|
return ret;
|
}
|
|
// called within scope of a series
|
function parseTrendLineOptions (target, data, seriesDefaults, options, plot) {
|
if (this._type && (this._type === 'line' || this._type == 'bar')) {
|
this.trendline = new $.jqplot.Trendline();
|
options = options || {};
|
$.extend(true, this.trendline, {color:this.color}, seriesDefaults.trendline, options.trendline);
|
this.trendline.renderer.init.call(this.trendline, null);
|
}
|
}
|
|
// called within scope of series object
|
function drawTrendline(sctx, options) {
|
// if we have options, merge trendline options in with precedence
|
options = $.extend(true, {}, this.trendline, options);
|
|
if (this.trendline && options.show) {
|
var fit;
|
// this.renderer.setGridData.call(this);
|
var data = options.data || this.data;
|
fit = fitData(data, this.trendline.type);
|
var gridData = options.gridData || this.renderer.makeGridData.call(this, fit.data);
|
this.trendline.renderer.draw.call(this.trendline, sctx, gridData, {showLine:true, shadow:this.trendline.shadow});
|
}
|
}
|
|
function regression(x, y, typ) {
|
var type = (typ == null) ? 'linear' : typ;
|
var N = x.length;
|
var slope;
|
var intercept;
|
var SX = 0;
|
var SY = 0;
|
var SXX = 0;
|
var SXY = 0;
|
var SYY = 0;
|
var Y = [];
|
var X = [];
|
|
if (type == 'linear') {
|
X = x;
|
Y = y;
|
}
|
else if (type == 'exp' || type == 'exponential') {
|
for ( var i=0; i<y.length; i++) {
|
// ignore points <= 0, log undefined.
|
if (y[i] <= 0) {
|
N--;
|
}
|
else {
|
X.push(x[i]);
|
Y.push(Math.log(y[i]));
|
}
|
}
|
}
|
|
for ( var i = 0; i < N; i++) {
|
SX = SX + X[i];
|
SY = SY + Y[i];
|
SXY = SXY + X[i]* Y[i];
|
SXX = SXX + X[i]* X[i];
|
SYY = SYY + Y[i]* Y[i];
|
}
|
|
slope = (N*SXY - SX*SY)/(N*SXX - SX*SX);
|
intercept = (SY - slope*SX)/N;
|
|
return [slope, intercept];
|
}
|
|
function linearRegression(X,Y) {
|
var ret;
|
ret = regression(X,Y,'linear');
|
return [ret[0],ret[1]];
|
}
|
|
function expRegression(X,Y) {
|
var ret;
|
var x = X;
|
var y = Y;
|
ret = regression(x, y,'exp');
|
var base = Math.exp(ret[0]);
|
var coeff = Math.exp(ret[1]);
|
return [base, coeff];
|
}
|
|
function fitData(data, typ) {
|
var type = (typ == null) ? 'linear' : typ;
|
var ret;
|
var res;
|
var x = [];
|
var y = [];
|
var ypred = [];
|
|
for (i=0; i<data.length; i++){
|
if (data[i] != null && data[i][0] != null && data[i][1] != null) {
|
x.push(data[i][0]);
|
y.push(data[i][1]);
|
}
|
}
|
|
if (type == 'linear') {
|
ret = linearRegression(x,y);
|
for ( var i=0; i<x.length; i++){
|
res = ret[0]*x[i] + ret[1];
|
ypred.push([x[i], res]);
|
}
|
}
|
else if (type == 'exp' || type == 'exponential') {
|
ret = expRegression(x,y);
|
for ( var i=0; i<x.length; i++){
|
res = ret[1]*Math.pow(ret[0],x[i]);
|
ypred.push([x[i], res]);
|
}
|
}
|
return {data: ypred, slope: ret[0], intercept: ret[1]};
|
}
|
|
})(jQuery);
|
