**nodejs-plotter** is a [node.js](http://nodejs.org/) module that turns an array of data into a graph in a [pdf](http://www.adobe.com/products/acrobat/adobepdf.html) document. Uses [gnuplot](http://www.gnuplot.info/) and [ps2pdf](http://pages.cs.wisc.edu/~ghost/doc/AFPL/6.50/Ps2pdf.htm).

## Installation ##

```
sudo apt-get install gnuplot ghostscript
```

You can add this to your [node.js](http://nodejs.org/) [package.json](http://docs.nodejitsu.com/articles/getting-started/npm/what-is-the-file-package-json)

```json
	"dependencies": {
		"plotter": "git+ssh://git@github.com:richardeoin/nodejs-plotter.git",
	}
```

And if you have [npm](https://npmjs.org/) installed, just run `npm install`.

I might put this on the [npm](https://npmjs.org/) registry in the future.

## Usage ##

```javascript
var plot = require('plotter').plot;

plot({
	data:		[ 3, 1, 2, 3, 4 ],
	filename:	'output.pdf'
});
```

Plotting is achieved by calling the plot function with an object containing various properties. Both `'data'` and `'filename'` are essential, all other properties are optional.

### Formatting ###

The following properties can be used:
* `title` - _Sets the title of the graph_
* `xlabel` - _Sets the label on the x axis of the graph_
* `ylabel` - _Sets the label on the y axis of the graph_
* `logscale` - _Makes the y axis of the graph appear in a log scale_
* `style` - _The style of the lines on the graph. Possibilites include `lines` (default), `points` and `linespoints`_

The following example shows these in use:

```javascript
plot({	
	data:		[ 3, 1, 2, 3, 4 ],
	filename:	'output.pdf',
	style:		'linespoints',
	title:		'Example \'Title\', \\n runs onto multiple lines',
	logscale:	true,
	xlabel:		'time',
	ylabel:		'length of string'
});
```

### Specifing X and Y values ###

```javascript
plot({
	data:		{ 'line' : { 1: 5, 5: 6 } },
	filename:	'output.pdf'
});
```

Instead of specifing an array for `data`, you can specify an object with a named series inside.

### Multiple Series ###

```javascript
plot({
	data:		{ 'tick' : [ 3, 1, 2, 3, 4 ], 'line' : { 1: 5, 5: 6 } },
	filename:	'output.pdf'
});
```

You can specify multiple series inside an object.

### Moving Averages and Maximums ###

```javascript
plot({
	data:		{ 'tick' : [ 3, 1, 2, 3, 4, 15, 3, 2, 4, 11 ], 'tick2' : [ 3, 10, 2, 30, 4, 15, 3, 20, 4, 11 ] },
	filename:	'output.pdf',
	moving_avg:	4
});
```

This will plot the points with a 4-point moving average. A `moving_max` can also be specified, which if applied alongside a `moving_avg` will be calculated after the moving average.

### Time Formatting ###

```javascript
plot({
	data:		{ 'temperature' : { 1357162672: 22, 1357162782: 23, 1357162892: 24 } },
	time:		'hours',
	filename:	'output.pdf'
});
```

The x axis can be formatted as a time series if the x values are given as a [unix time](http://en.wikipedia.org/wiki/Unix_time). The `time` property can be specified as either `'hours'` (the default), `'days'` or with a [gnuplot time format](http://gnuplot.sourceforge.net/docs_4.2/node274.html) like `'%H:%M'`.

## LICENSE ###

MIT