Re: [Gnuplot-py-users] Problem using gnuplot.py from cron on cygwin under W2K

[<kai...@t-...>]

Hi,

My guess is that "gnuplot: not found" indicates that the gnuplot program 
(not the Python package but the program itself) is not in your PATH.

If that is not the case, make sure that you don't have problems with 
temporary files being deleted before they are used.  The FAQ.txt file in 
the latest CVS version of Gnuplot.py has more information about this 
well-known problem.

If you are interested in Gnuplot.py issues, you might consider 
subscribing to the mailing list.  You can do that through SourceForge,

    http://sourceforge.net/projects/gnuplot-py

Let me know if it helps,
Michael

Michael T. Colee wrote:

> Hello and thanks for the efforts on gnuplot.py, really a nice tool.  
> I'm hoping you might have some insight into a problem I'm having as a 
> relatively new python and gnuplot.py user.
>
> I've written a rather brute force script that generates png plots  of 
> various meteorological fields for posting on a web page.  When I run 
> it from the command line it functions beautifully and generates all my 
> plots in the locations I want them.  If you are curious to see the 
> results what I'm doing you can look at:
>
> http://neige.bren.ucsb.edu/mmsa/images/weekly/default.htm
> &
> http://neige.bren.ucsb.edu/mmsa/images/daily/default.htm
>
> When I go to run the routine scheduled from a cron entry however, it 
> chokes.  The system I'm on is running W2K server and I've got cron 
> running under cygwin which calls various scripts every hour to 
> generate the pages I need.  Other python scripts work fine in this 
> manner, for example, the following page:
>
> http://neige.bren.ucsb.edu/mmsa/images/hourly/LatestMet.htm
>
> is automatically generated hourly from a seperate python script called 
> from the same cron entry.
>
> So, the code (Plotmmsa.py) I'm having trouble with is:
>
> _________________________________________________________
> #...bunch of prep stuff cut out for brevity...
> print "Read in and set various lists, starting plots. Last depth 
> reading:"
> print PlatformTemp[-1:] #make sure we've got data in our lists (we do).
>
> #g = Gnuplot.Gnuplot()
> g = Gnuplot.Gnuplot(debug=1) #debug=1 outputs gnuplot commands to stdout
> g('set data style lines')
> #g('set data style linespoints')
> g('set term png color')
>
>
> g.title('Temperature')
> g.xlabel('Day of Year')
> g.ylabel('Degrees C')
> #This is line 106 which seems to be the problem:
> g('set output "/home/mmsa/wwwroot/mmsa/images/weekly/PlatformTemp.png"')
> g.plot(PlatformTemp[-700:]) #Plot the last 7 days of data.
> time.sleep(1)        #Wait for gnuplot to do it's thing.
> g('set output "/home/mmsa/wwwroot/mmsa/images/daily/PlatformTemp.png"')
> g.plot(PlatformTemp[-96:])  #Plot the last day of data.
> time.sleep(1)        #Wait for gnuplot to do it's thing.
> #...Rest of plots left out for brevity...
> __________________________________________________________
>
>
> Output from running Plotmmsa.py at the command prompt:
>
> $ ../bin/python/Plotmmsa.py
> Read in and set various lists, starting plots. Last depth reading:
> [[7.458333333333333, 3.8610000000000002]]
> gnuplot> set data style lines
> gnuplot> set term png color
> gnuplot> set title "Temperature"
> gnuplot> set xlabel "Day of Year"
> gnuplot> set ylabel "Degrees C"
> gnuplot> set output 
> "/home/mmsa/wwwroot/mmsa/images/weekly/PlatformTemp.png"
> gnuplot> plot '/cygdrive/c/WINNT/TEMP/@1648.0' notitle
> gnuplot> set output 
> "/home/mmsa/wwwroot/mmsa/images/daily/PlatformTemp.png"
> gnuplot> plot '/cygdrive/c/WINNT/TEMP/@1648.1' notitle
> __________________________________________________________
>
> Output from cron running the same program:
>
> gnuplot> set data style lines
> gnuplot> set term png color
> gnuplot> set title "Temperature"
> gnuplot> set xlabel "Day of Year"
> gnuplot> set ylabel "Degrees C"
> gnuplot> set output 
> "/home/mmsa/wwwroot/mmsa/images/weekly/PlatformTemp.png"
> gnuplot> plot '/cygdrive/c/WINNT/TEMP/@1984.0' notitle
> gnuplot: not found
> Read in and set various lists, starting plots. Last depth reading:
> [[7.458333333333333, 3.8610000000000002]]
> Traceback (most recent call last):
>   File "/home/mmsa/bin/python/Plotmmsa.py", line 106, in ?
>     g('set output 
> "/home/mmsa/wwwroot/mmsa/images/daily/PlatformTemp.png"')
>   File "/usr/lib/python2.2/site-packages/Gnuplot/_Gnuplot.py", line 
> 206, in __call__
>     self.gnuplot(s)
>   File "/usr/lib/python2.2/site-packages/Gnuplot/gp_unix.py", line 
> 203, in __call__
>     self.flush()
> IOError: [Errno 32] Broken pipe
>
> _________________________________________________________
>
> Any suggestions would be much appreciated.  My next step will be to 
> get gnuplot.py running on a linux box and see if I have the same 
> problems there.
>
> Thanks in advance,
> mtc
>


-- 
Michael Haggerty
mh...@al...