RE: [Gnuplot-py-users] Re: Time/Date data in Gnuplot-py

[chuck c. <cc...@zi...>]

Leo,
The mxdate package which Michael speaks of is a great package indeed and
handles datetime data very well and has almost any date/time functions you
could think of.  I think my problem lies in the fact of I'm not sure which
PlotItem type from gnuplot-py I should use.  I was originally trying to use
Data but of course "12:01" can't be converted to a Numeric Float array.  So
now I'm taking a step back and wondering if I need to create my own PlotItem
types of Date, Time and DateTime to do this?

I thought about doing as you say about converting my hh:mm:ss string into a
float but it isn't really clean because time is base 60 and not decimal and
I lose a lot of readability because suddenly my x-axis is not regular times
that the user would expect to see but some decimal representation of it.  If
I somehow try to preserve the time by making 12:01 into 1201 then I'll have
funny gaps from 1260 to 1300 and on every other hour.

Gnuplot itself handles Date/Time types as seen in the 3.7.1 manual.  If you
had the data below in a file called test.dat you could plot it in Gnuplot
with the following:

12:01    4.63
12:02    6.74
12:03    0.0
12:04    6.32

gnuplot> set xdata time
gnuplot> set timefmt "%H:%M"
gnuplot> set format x "%H:%M"
gnuplot> set xrange ["12:00":"12:05"]
gnuplot> plot "/home/cclark/test.dat" using 1:2

So I guess what I was wondering was if anyone had plotted date/time data
using gnuplot-py with the existing PlotItem types or if people who were more
familiar with the package than I am thought I'd need to come up with a new
type.  Any thoughts would be greatly appreciated.

cheers,
chuck