The two scripts in this directory download and plot data from a dl2.
"plot" is the script invoked by the user. It in turn invokes "update".

Downloaded data is stored in a subdirectory Archive. The archive is
automatically kept up to date by the scripts. When pplot is run, if
the archive file is not up to date as of the previous night at
midnight, any required data is downloaded to bring it up to date.

Then another download is run to get today's data from midnight up to the
current time.

Then the data is pruned to the desired dates and a gnuplot script is
generated.  Finally gnuplot is run and the graph is displayed.

The archiving feature makes it unnecessary to worry about the memory
capacity of the DL2 --- all data is stored on the development machine
and graphs can be generated to display any set of historical data -
from a few minutes to years in one graph.

These scripts run on macosx 10.6 using gnuplot from macports, and the
graph is displayed using Aquaterm. (The version of gnuplot supplied
with Homebrew does not work with Aquaterm. Instead run gnuplot in an
Xterm and the data will display in an X11 window. The graph doesn't
look as nice but it does have a feature of having a live cursor which
can read out precise values.)

The scripts can probably be ported to linux fairly easily. Use curl or
wget instead of lwp-download for downloading the data from the
DL2. The script is also dependent on the options for the 'date'
command -- it uses them directly so if there's any difference in those
options it may be necessary to make some adjustments.

Finally, there is a "-w" option which is probably not useful to anyone
but me, so I am not supplying the scripts which this option
invokes. It downloads and graphs additional temperature data from some
Weather Direct sensors, and it relies very specifically on my Mac
environment using Safari and 1Password.

INSTALLATION AND USE:

Install gnuplot and aquaterm from macports.
Unpack this archive in a clean directory.
Edit the plot file enter the appropriate values of TZ and site
cd to the directory and run ./plot
For more info on usage, run ./plot -h 
 (the script always has to run in the current directory -- it will
  create its data archives in that directory).

FILES
 README
 License.txt
 plot
 update
 Examples/*.pdf