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Groups > comp.graphics.apps.gnuplot > #1458

Re: plotting data directly from an Internet link?

Newsgroups comp.graphics.apps.gnuplot
Date 2012-10-31 06:44 -0700
References <cf7a8cca-4187-432d-84f9-1c6df0bf7871@googlegroups.com> <k6nbur$pep$1@dont-email.me> <9ceb5771-afd5-4a4e-b90e-00f8f283626a@googlegroups.com> <k6qef5$2ac$1@dont-email.me>
Message-ID <c1f7353a-7493-447f-b2bb-2b116286df67@googlegroups.com> (permalink)
Subject Re: plotting data directly from an Internet link?
From TonyG <tgozdz@gmail.com>

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On Wednesday, October 31, 2012 1:54:46 AM UTC-4, sfeam wrote:
> TonyG wrote:
> 
> 
> 
> > On Monday, October 29, 2012 9:53:32 PM UTC-4, sfeam wrote:
> 
> >> TonyG wrote:
> 
> >> 
> 
> >> 
> 
> >> 
> 
> >> > Is it possible to use an Internet link to some column-formatted
> 
> >> > data
> 
> >> 
> 
> >> > as the data source for the 'file' part of the 'plot' command?
> 
> >> 
> 
> >> > 
> 
> >> 
> 
> >> > A good example would be plotting selected columns from
> 
> >> 
> 
> >> > http://www.ndbc.noaa.gov/data/5day2/44013_5day.txt
> 
> >> 
> 
> >> > 
> 
> >> 
> 
> >> > BTW, since I use a WinXP OS, I doubt I could use the pop(x) method
> 
> >> > as
> 
> >> 
> 
> >> > described in the Help file, e.g.,
> 
> >> 
> 
> >> > 
> 
> >> 
> 
> >> > pop(x) = 103*exp(-x/10)
> 
> >> 
> 
> >> > plot "< awk '{print $1-1965, $2}' population.dat", pop(x)
> 
> >> 
> 
> >> 
> 
> >> 
> 
> >> 
> 
> >> 
> 
> >> You say "I doubt I could use....".
> 
> >> 
> 
> >> But have you actually tried it?
> 
> > 
> 
> > Now I have... ;-)
> 
> > 
> 
> >> 
> 
> >> So long as the gnuplot executable supports pipes, you should
> 
> >> 
> 
> >> be OK.
> 
> > 
> 
> > Yes, I'm using gnuplot_pipes as my default executable.  (BTW, why are
> 
> > there two versions if gnuplot_pipes has more capabilities; is there
> 
> > something missing in it in comparison to std. gnuplot?)
> 
> 
> 
> Good question.  I'm not a Windows user, but my understanding is
> 
> that the distinction went away in version 4.6 because all the 
> 
> functionality of both the previous versions is in the single
> 
> executable gnuplot.exe
> 
> 
> 
> 
> 
> >> At least under linux one answer is
> 
> >> 
> 
> >>   plot "< GET http://www.ndbc.noaa.gov/data/5day2/44013_5day.txt"
> 
> >> 
> 
> >> 
> 
> >> 
> 
> >> where GET is a widely-distributed perl script roughly equivalent
> 
> >> 
> 
> >> to wget.  If you prefer wget, then
> 
> >> 
> 
> >>   plot "< wget -O -
> 
> >>   http://www.ndbc.noaa.gov/data/5day2/44013_5day.txt"
> 
> > 
> 
> > Thanks; wget works, and downloads and displays the data when used from
> 
> > the command line.  However, it bombs out when used inside gnuplot:
> 
> > 
> 
> > gnuplot> plot "< wget -O -
> 
> > http://www.ndbc.noaa.gov/data/5day2/44013_5day.txt" using ($13) w lp
> 
> >          warning: Skipping unreadable file "< wget -O -
> 
> >          http://www.ndbc.noaa.gov/data/5day2/44013_5day.txt" No data
> 
> >          in plot
> 
> > 
> 
> > The input file has a two-row header:
> 
> > 
> 
> > #YY  MM DD hh mm WDIR WSPD GST  WVHT   DPD   APD MWD   PRES  ATMP 
> 
> > #WTMP  DEWP  VIS PTDY  TIDE
> 
> > #yr  mo dy hr mn degT m/s  m/s     m   sec   sec degT   hPa  degC 
> 
> > #degC  degC  nmi  hPa    ft
> 
> > 2012 10 30 14 50 120  6.0  8.0   3.1    11   7.2 104 1001.2  14.0 
> 
> > 12.4  12.5   MM +2.8    MM
> 
> > 2012 10 30 13 50 130  8.0  9.0   3.3    10   7.6  95 1000.4  14.1 
> 
> > 12.4  12.6   MM +2.6    MM
> 
> > 
> 
> > but in my experience gnuplot handles such cases easily...  I have
> 
> > tried various changes, but to no avail--I'm stuck.
> 
> 
> 
> I don't know.  That command works for me under linux.
> 
> I get this output:
> 
> 
> 
> gnuplot> set term dumb
> 
> gnuplot> plot "< wget -O - http://www.ndbc.noaa.gov/data/5day2/44013_5day.txt" using ($13) w lp
> 
> --2012-10-30 22:53:12--  http://www.ndbc.noaa.gov/data/5day2/44013_5day.txt
> 
> Resolving www.ndbc.noaa.gov (www.ndbc.noaa.gov)... 140.90.238.27
> 
> Connecting to www.ndbc.noaa.gov (www.ndbc.noaa.gov)|140.90.238.27|:80... connected.
> 
> HTTP request sent, awaiting response... 200 OK
> 
> Length: 11468 (11K) [text/plain]
> 
> Saving to: “STDOUT”
> 
> 
> 
> 100%[============================================>] 11,468      48.3K/s   in 0.2s    
> 
> 
> 
> 2012-10-30 22:53:13 (48.3 KB/s) - written to stdout [11468/11468]
> 
> 
> 
>   1025 ++---------+-----------+----------+----------+-----------+----AA-AAA+
> 
>        +          +           +          +          +           +   AAAAA+ +
> 
>   1020 ++                                                    AAAAAAA      ++
> 
>        |                                               AAAAAAA             |
> 
>        |                                       AAAAAAAAA                   |
> 
>   1015 ++                                AAAAAAA                          ++
> 
>        |                             AA A                                  |
> 
>   1010 ++                           A  A                                  ++
> 
>        |                           A                                       |
> 
>        |                         AA                                        |
> 
>   1005 ++                       A                                         ++
> 
>        | A AAAAA              AA                                           |
> 
>   1000 AA A    AA            AA                                           ++
> 
>        |         AA          A                                             |
> 
>    995 ++         AA        A                                             ++
> 
>        |            AA     A                                               |
> 
>        |              A A  A                                               |
> 
>    990 ++              A AA                                               ++
> 
>        +          +           +          +          +           +          +
> 
>    985 ++---------+-----------+----------+----------+-----------+---------++
> 
>        0          20          40         60         80         100        120

And now, suddenly and for an unexplained reason, I am getting the same result as yours, both with dumb and windows terminals.

You've been most helpful, thank you.

--Tony

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Thread

plotting data directly from an Internet link? TonyG <tgozdz@gmail.com> - 2012-10-29 10:15 -0700
  Re: plotting data directly from an Internet link? James <jjpuzzles@wowway.com> - 2012-10-29 13:00 -0700
    Re: plotting data directly from an Internet link? TonyG <tgozdz@gmail.com> - 2012-10-29 15:19 -0700
  Re: plotting data directly from an Internet link? sfeam <sfeam@users.sourceforge.net> - 2012-10-29 18:53 -0700
    Re: plotting data directly from an Internet link? TonyG <tgozdz@gmail.com> - 2012-10-30 08:56 -0700
      Re: plotting data directly from an Internet link? sfeam <sfeam@users.sourceforge.net> - 2012-10-30 22:54 -0700
        Re: plotting data directly from an Internet link? TonyG <tgozdz@gmail.com> - 2012-10-31 06:44 -0700

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