I wanted to share a script I use for analyzing sensor data stored on Pachube. I use the open source stats software R which is available on most platforms. The simple script below consists of only two functions:
Pachube.fetch. Query allows me to inspect a particular feed which can be made of zero or more datastreams.
Pachube.fetch retrieves data points up to a given number of hours in the past.
Authentication happens through the getURL call. By specifying netrc ‘optional’ RCurl looks for a separate
.netrc file in your home directory:
machine api.pachube.com login _your login_ password _your password_
_your login_ and
_your password_ with the appropriate information.
Save the file locally as “Pachube.R” and launch R. You can load the script as follows:
Once loaded, query a feed as follows:
This will display the datastreams available from an #AirQualityEgg assembled in London during a workshop. To retrieve the NO2 data issue the following command
Pachube.fetch(feed=48307, datastream="NO2", hours=24)
The maximum number of data points available through the historical query API is described here. Writing these was good fun and a way for me to keep learning R…
This material is licensed under a Creative Commons Attribution 3.0 Unported License