X-Git-Url: https://adrianiainlam.tk/git/?a=blobdiff_plain;f=docs%2Findex.html;h=4ea19c81f33e312c289c1a8001183c8658c330de;hb=2a6bfbd41d6302df34c788c2c63965a351fcb59e;hp=faf5554a79f395bbdaad0578a3aeac57aa6e0622;hpb=6153f697b779d1cb001700beacb443d75fcc5914;p=dygraphs.git diff --git a/docs/index.html b/docs/index.html index faf5554..4ea19c8 100644 --- a/docs/index.html +++ b/docs/index.html @@ -23,11 +23,11 @@ -

dygraphs JavaScript Library
- (Contact: Dan Vanderkam)

dygraphs JavaScript Library
+ code.google.com/p/dygraphs

The dygraphs JavaScript library produces produces interactive, zoomable charts of time series based on CSV files.

The dygraphs JavaScript library produces produces interactive, zoomable charts of time series.

Features

Interactive zoom
Adjustable averaging period
Customizable click-through actions
Compatible with the Google Visualization API

Caveats

@@ -51,16 +52,17 @@

Usage

The DateGraph library depends on two other JS libraries: MochiKit and PlotKit. Rather than tracking down copies of these libraries, I recommend using a packed version of dygraphs that combines all three libraries into a single JS file. Either grab this file from dygraph project's downloads page or create it yourself by checking out a copy of the code and running: +

The dygraphs library depends on two other JS libraries: MochiKit and PlotKit. Rather than tracking down copies of these libraries, I recommend using a packed version of dygraphs that combines all three libraries into a single JS file. Either grab this file from dygraph project's downloads page or create it yourself by checking out a copy of the code and running:

./generate-combined.sh

@@ -103,39 +106,33 @@ <script type="text/javascript" src="combined.js"></script> </head> <body> -<div id="graphdiv" style="width:400px; height:300px;"></div> +<div id="graphdiv"></div> <script type="text/javascript"> - g = new DateGraph( + g = new Dygraph( document.getElementById("graphdiv"), // containing div - function() { // function or path to CSV file. - return "20080507,75\n" + - "20080508,70\n" + - "20080509,80\n"; - }, - [ "Temperature" ], // names of data series - {} // additional options (see below) + "Date,Temperature\n" + // CSV or path to a CSV file. + "20080507,75\n" + + "20080508,70\n" + + "20080509,80\n", ); </script> </body> </html> -

In order to keep this example self-contained, the second parameter is a function that returns CSV data. These lines must begin with a date in the form YYYYMMDD. In most applications, it makes more sense to include a CSV file instead. If the second parameter to the constructor is a string, it will be interpreted as the path to a CSV file. The DateGraph will perform an XMLHttpRequest to retrieve this file and display the data when it becomes available. Make sure your CSV file is readable and serving from a place that understands XMLHttpRequest's! In particular, you cannot specify a CSV file using "file:///". Here's an example: (data from Weather Underground)

In order to keep this example self-contained, the second parameter is a function that returns CSV data. These lines must begin with a date in the form YYYYMMDD. In most applications, it makes more sense to include a CSV file instead. If the second parameter to the constructor is a string, it will be interpreted as the path to a CSV file. The Dygraph will perform an XMLHttpRequest to retrieve this file and display the data when it becomes available. Make sure your CSV file is readable and serving from a place that understands XMLHttpRequest's! In particular, you cannot specify a CSV file using "file:///". Here's an example: (data from Weather Underground)

@@ -150,11 +147,10 @@ <body> <div id="graphdiv" style="width:600px; height:300px;"></div> <script type="text/javascript"> - g = new DateGraph( + g = new Dygraph( document.getElementById("graphdiv"), "temperatures.csv", // path to CSV file - null, // labels in top line of CSV file - {} + {} // additional options ); </script> </body> @@ -163,9 +159,9 @@

HTML

@@ -173,14 +169,15 @@

Click here to view the temperatures.csv file. There are a few things to note here:

Because the third parameter to the DateGraph constructor was null, the labels were taken from the first line of the data instead. The first line of temperatures.csv is Date,High,Low.
DateGraph automatically chose two different, easily-distinguishable colors for the two data series.
The Dygraph sent off an XHR to get the temperatures.csv file.
The labels were taken from the first line of temperatures.csv, which is Date,High,Low.
The Dygraph automatically chose two different, easily-distinguishable colors for the two data series.
The labels on the x-axis have switched from days to months. If you zoom in, they'll switch to weeks and then days.
Some heuristics are used to determine a good vertical range for the data. The idea is to make all the data visible and have human-friendly values on the axis (i.e. 200 instead of 193.4). Generally this works well, but in this case the vertical range is way too large.
Some heuristics are used to determine a good vertical range for the data. The idea is to make all the data visible and have human-friendly values on the axis (i.e. 200 instead of 193.4). Generally this works well.
The data is very spiky. A moving average would be easier to interpret.

These last two problems can be fixed by specifying the appropriate options in the fourth parameter to the DateGraph constructor. To set the number of days for a moving average, use the rollPeriod option. To set the range of the y-axis, use the valueRange option. Here's how it's done:

This problem can be fixed by specifying the appropriate options in the "additional options" parameter to the Dygraph constructor. To set the number of days for a moving average, use the rollPeriod option. Here's how it's done:

@@ -195,11 +192,11 @@ <body> <div id="graphdiv" style="width:600px; height:300px;"></div> <script type="text/javascript"> - g = new DateGraph( + g = new Dygraph( document.getElementById("graphdiv"), - "temperatures.csv", null, + "temperatures.csv", { rollPeriod: 7, - valueRange: [25, 100] + showRoller: true, } ); </script> @@ -209,20 +206,20 @@

HTML

A rolling average can always be set using the text box in the lower left-hand corner of the graph.

A rolling average can be set using the text box in the lower left-hand corner of the graph (the showRoller attribute is what makes this appear).

Error Bars

Another significant feature of the dygraphs library is the ability to display error bars around data series. One standard deviation must be specified for each data point. A +/-n sigma band will be drawn around the data series at that point. If a moving average is being displayed, DateGraph will compute the standard deviation of the average at each point. (i.e. σ = sqrt((σ_1^2 + σ_2^2 + ... + σ_n^2)/n))

Another significant feature of the dygraphs library is the ability to display error bars around data series. One standard deviation must be specified for each data point. A +/-n sigma band will be drawn around the data series at that point. If a moving average is being displayed, dygraphs will compute the standard deviation of the average at each point. (i.e. σ = sqrt((σ_1^2 + σ_2^2 + ... + σ_n^2)/n))

Here's a demonstration. There are two data series. One is N(100,10) with a standard deviation of 10 specified at each point. The other is N(80,20) with a standard deviation of 20 specified at each point. The CSV file was generated using Octave and can be viewed here.

@@ -243,11 +240,11 @@ ></div> <script type="text/javascript"> $ = document.getElementById; -g = new DateGraph( +g = new Dygraph( $("graphdiv"), "twonormals.csv", - null, { rollPeriod: 7, + showRoller: true, errorBars: true, valueRange: [50,125] } @@ -260,11 +257,11 @@ g = new DateGraph(

+ + +

Other Options

These are the options that can be passed in through the fourth parameter of the DateGraph constructor.

These are the options that can be passed in through the optional third parameter of the Dygraph constructor.

@@ -290,6 +323,10 @@ new DateGraph( + + + +

Name	Sample Value	Description
`7`	Number of days over which to average data. Discussed extensively above.
showRoller	`true`	Should the rolling average period text box be shown? Default is false.
colors	`['red', '#00FF00']`	List of colors for the data series. These can be of the form "#AABBCC" @@ -366,7 +403,7 @@ new DateGraph(

Any options you specify also get passed on to PlotKit's Renderer class. DateGraph will override some of these (e.g. strokeColor), but others may be useful. The padding property is an example of this.

Any options you specify also get passed on to PlotKit's Renderer class. dygraphs will override some of these (e.g. strokeColor), but others may be useful. The padding property is an example of this.

Common Gotchas

Here are a few problems that I've frequently run into while using the @@ -379,22 +416,15 @@ dygraphs library.

href="http://www.getfirebug.com/">Firebug.

Make sure your CSV files are in the correct format. They must be of the - form YYYYMMDD,series1,series2,.... If you're specifying the - names of each data series in the CSV file itself, make sure that you pass - null as the third parameter to the DateGraph constructor to let - the library know that. And if you set the errorBars property, - make sure you alternate data series and standard deviations.

+ form YYYYMMDD,series1,series2,.... And if you set the + errorBars property, make sure you alternate data series and + standard deviations.

dygraphs are not happy when placed inside a <center> tag. This applies to the CSS text-align property as well. If you - want to center a DateGraph, put it inside a table with "align=center" + want to center a Dygraph, put it inside a table with "align=center" set.

If you specify the colors property or name the data series - using the third parameter of the DateGraph constructor, make sure the number - of data series agree in all places: colors, third parameter and - in each line of the CSV file itself.

Don't set the dateWindow property to a date. It expects milliseconds since epoch, which can be obtained from a JavaScript Date object's valueOf method.