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Groups > comp.graphics.apps.gnuplot > #3727

Re: Ephemerides data

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On Tuesday, August 22, 2017 at 7:09:32 PM UTC+2, Karl Ratzsch wrote:
> Am 22.08.2017 um 16:57 schrieb robertvanpass@gmail.com:
> >>
> >>> However I still have an issue:
> >>>
> >>> When I add the code for the timezone specifier ( +strcol(3)[4:8]*3600) )
> >>> I get the errormessage "Non-numeric string found where a numeric expression was expected"
> >>>
> >>
> >> gnuplot automatically converts strings to numberic variables in
> >> expressions (i.e. if you do math like *1.0) if possible.
> >>
> >> Can you make an example like the one above that I can directly copy
> >> into gnuplot to reproduce your problem?
> > 
> > No problem:
> > 
> > 1. Putting these lines in a CSV file will give the errormessage:
> > 
> 
> I meant *exactly* ;-) like this:
> 
> ---- gnuplot input ----
> $dat << EOD
> 8/20/2017;12:00:00 UTC+1.0;10h 35m 50.60s;+03° 47' 15.38";
> 8/21/2017;12:00:00 UTC+1.0;10h 33m 13.63s;+04° 02' 23.70";
> 8/22/2017;12:00:00 UTC+1.0;10h 30m 23.99s;-04° 20' 34.64";
> EOD
> 
> set dataf sep "; "
> set table
> 
> plot $dat us \
> (timecolumn(1,"%d/%m/%Y")):\
> (timecolumn(2,"%H:%M:%S")+strcol(3)[4:8]*3600):\
> (timecolumn(4,"%Hh %Mm %Ss")/3600):\
> (($7 + ($7<0?-$8:$8)/60 + ($7<0?-$9:$9)/3600)) w table
> ---- end ----
> 
> , only with the plot command that fails for you.
> 
> Then I can just c&p the whole thing into the gnuplot console, without
> creating files and guessing at your exact plot setup.
> 
> The negative declinations come out wrong because the minutes and seconds
> get the wrong sign then. I fixed the above plot command to take that
> into account.
> 
>   K



Got it !

I use a slightly different plot command to correct for declination values between -00° and -01°, but basically it's like you say.

Now the last hurdle for me is that the X-axis of the graph is not in a readable Date-Time format:

$dat << EOD
8/20/2017;12:00:00 UTC+1.0;10h 35m 50.60s;+03° 47' 15.38";
8/21/2017;12:00:00 UTC+1.0;10h 33m 13.63s;+04° 02' 23.70";
8/22/2017;12:00:00 UTC+1.0;10h 30m 23.99s;-04° 20' 34.64";
EOD

set dataf sep "; "
set table 'ephem'
set term qt 1
plot $dat us \
(timecolumn(1,"%d/%m/%Y")):\
(timecolumn(2,"%H:%M:%S")+strcol(3)[4:8]*3600):\
(timecolumn(4,"%Hh %Mm %Ss")/3600):\
(($7 + ($7<0?-$8:$8)/60 + ($7<0?-$9:$9)/3600)) w table 
unset table

plot 'ephem' u 2:4 w lp, \
                  '' u 2:5 w lp

Do you have an idea how to get date and time on the X-axis of the graph ?

Thank you very much !

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Ephemerides data robertvanpass@gmail.com - 2017-08-20 06:36 -0700
  Re: Ephemerides data Karl Ratzsch <mail.kfr@gmx.net> - 2017-08-20 22:56 -0300
    Re: Ephemerides data Karl Ratzsch <mail.kfr@gmx.net> - 2017-08-20 23:59 -0300
      Re: Ephemerides data robertvanpass@gmail.com - 2017-08-21 15:01 -0700
        Re: Ephemerides data Karl Ratzsch <mail.kfr@gmx.net> - 2017-08-22 03:59 +0200
          Re: Ephemerides data robertvanpass@gmail.com - 2017-08-22 07:57 -0700
            Re: Ephemerides data Karl Ratzsch <mail.kfr@gmx.net> - 2017-08-22 19:09 +0200
              Re: Ephemerides data robertvanpass@gmail.com - 2017-08-22 14:09 -0700
                Re: Ephemerides data Karl Ratzsch <mail.kfr@gmx.net> - 2017-08-23 01:45 +0200
                Re: Ephemerides data robertvanpass@gmail.com - 2017-08-23 13:09 -0700

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