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.
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 +105,33 @@ <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)
| HTML | @@ -150,11 +146,10 @@ <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 +158,9 @@
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Click here to view the temperatures.csv file. There are a few things to note here:
null, the labels were taken from the first line of the data instead. The first line of temperatures.csv is Date,High,Low.temperatures.csv, which is Date,High,Low.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:
| HTML | @@ -195,12 +191,11 @@ <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, showRoller: true, - valueRange: [25, 100] } ); </script> @@ -210,12 +205,11 @@
@@ -224,7 +218,7 @@
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 |
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