These days I’m investigating the use of pChart for the graphical representation of all measurements to be collected by my domotica solution. If we collect sensor data the database will be filled with thousands of records. Records in a database are of no value if we don’t convert them to a nice representation. This can be done by generating charts, so we can see e.g. how a temperature changes over time.
Searching the internet I found pChart as a PHP solution for creation of wonderful charts of all kind. Their site is shows numerous examples of line, pie, bar, etc. charts.
It is easy to make a professional chart using database logging together with the pChart classes. The style can be customized and their are abilities to add image maps to get dynamic feedback.
In the picture below you see an example of a chart with the average temperature per hour.
The x-axis shows the week number (of the year) – day number (of the week) – hour (of the day).
We can see the temperature go down a bit in the night and go up again in the morning.
Over time we can learn a lot about e.g. temperature, humidity, pressure, … when enough data is collected. Of course we can use several representations of the data depending of the period that has been logged and the type of data. When electricity consumption is collected it is of course possible to create a chart with the cost per period.