Hi all -
I thought I'd chime in and add to this dusty thread. I found what I think is a perfect companion to Housebot for plotting data trends. It is "gnuplot" and you can find it here:
http://www.gnuplot.info/
It is freeware and it has a GUI and a command line interface. The GUI is perfect for testing and debugging the plot files. Once the plot files are good to go, Housebot will happily execute the command line version and you can load the resulting plots into Housebot as PNG images (dynamic images). It does all kinds of plots, 3-D plots, polar, etc. It will also let you specify the output image sizes and will even rotate text along the bottom axis by 90 degrees! It's a plotter's wet dream come true.
A couple of Caveats:
1) gnuplot is kinda hard to use - once you've practiced using the sample plot files and reading the manual (over and over), it will come together. The hardest part for me was trying to get my date and time formats to be read in from a file. It was kinda tricky.
2) gnuplot claims to support "GIF" but not really, they're really PNG images with a "GIF" extension. Very misleading - fortunately, HB understands PNG just fine - just make sure you use the "PNG" extension when specifying the output filename.
3) I had to use a custom VB script to create the plot files. Housebot's logging didn't cut it for me because it added too much data. For example, I wanted to plot a temperature trend, but the log file saves it as "Temperature Property Has Changed to [30]" or something like that (along with a time and date - still useful). gnuplot doesn't understand that format very well, it wants a file with numbers pretty much. I'm sure with enough blood and sweat, gnuplot can be configured to understand Housebot log data files directly. However, in order to put multiple plots onto one plot, the data still has to be in one file (I think). For Housebot to put multiple property values into a single log file would require some kind of composite property value to be created and then decomposed later by gnuplot. Too much work!!
So, my VB script, which was invoked at regular intervals, would append to a temperature log file containing the date, time, temperature, a high temperature, and a low temperature (I've got another script that keeps track of that stuff). Anyway, it works very well. I'm still testing it out and not sure how well the dynamic image is loading - I've had to use a trick that I found elsewhere in this forum to have a task wake up and refresh the filename of the dynamic image property to force it to update to all the SWRemotes.