Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.graphics.apps.gnuplot > #3246

Re: chart disappears when i add xrange / yrange to binary array plot of radio spectrogram data

From Hans-Bernhard Bröker <HBBroeker@t-online.de>
Newsgroups comp.graphics.apps.gnuplot
Subject Re: chart disappears when i add xrange / yrange to binary array plot of radio spectrogram data
Date 2016-03-01 20:54 +0100
Message-ID <djmabiFe9jrU1@mid.dfncis.de> (permalink)
References <8bd1c7cb-da40-4d20-a789-4e5c6ebd31a0@googlegroups.com>

Show all headers | View raw


Am 01.03.2016 um 14:58 schrieb Mario Cannistrà:

> For the same reason I'm storing only z values
> and NO x,y (timestamps, frequencies).

I suspect that's your problem right there.  Without the time stamps in 
the data, where are the x coordinates you want to limit the range to 
supposed to come from?

> When I try to uncomment the xrange and yrange statements, i get the
> axis labels correctly represented but the data area of the plot
> simply disappears.

That would be case, as-is, your data file does not actually hold any 
data inside the ranges you specified.

> Please see
> https://www.dropbox.com/s/n022h60lyvf57t1/plot-showing-spectrogram.png?dl=0
> for the plot with data and

If you take a good hard look at that, you may notice that the x axis is 
from timestamps 01:06:00 to about 01:07:18, on some unknown day.  That 
doesn't overlap with the range you pass to gnuplot:

> gnuplot -e "scanstart='160228082733'" -e "scanend='160228082833'"
[...]
> rangeonx = '["'.scanstart.'":"'.scanend.'"]'
[...]
> set format x "%H:%M:%S"
> set xrange @rangeonx

There are no data around 08:28 h in that file.

There is nothing in that plot script that would move the actual 
(implicit) data range of [0:7999] into the realm of time stamps you 
specify as your xrange.

Binary data in %float format wouldn't be able to hold the kind of 
resolution you're attempting, anyway: you're specifying a range of 60 
seconds, 16 years away from gnuplot's epoch of 2000-01-01.

	60 seconds / 16 years

only about twice as large as FLT_EPS, i.e. there are only three 
different single-precision %float numbers in that entire x range.

Back to comp.graphics.apps.gnuplot | Previous | NextPrevious in thread | Next in thread | Find similar


Thread

chart disappears when i add xrange / yrange to binary array plot of radio spectrogram data Mario Cannistrà <mariocannistra@gmail.com> - 2016-03-01 05:58 -0800
  Re: chart disappears when i add xrange / yrange to binary array plot of radio spectrogram data Mario Cannistrà <mariocannistra@gmail.com> - 2016-03-01 06:07 -0800
  Re: chart disappears when i add xrange / yrange to binary array plot of radio spectrogram data Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2016-03-01 20:54 +0100
    Re: chart disappears when i add xrange / yrange to binary array plot of radio spectrogram data Mario Cannistrà <mariocannistra@gmail.com> - 2016-03-01 13:07 -0800
      Re: chart disappears when i add xrange / yrange to binary array plot of radio spectrogram data Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2016-03-01 23:29 +0100
        Re: chart disappears when i add xrange / yrange to binary array plot of radio spectrogram data Mario Cannistrà <mariocannistra@gmail.com> - 2016-03-02 01:08 -0800
  Re: chart disappears when i add xrange / yrange to binary array plot of radio spectrogram data Karl Ratzsch <mail.kfr@gmx.net> - 2016-03-02 00:33 +0100
    Re: chart disappears when i add xrange / yrange to binary array plot of radio spectrogram data Mario Cannistrà <mariocannistra@gmail.com> - 2016-03-02 01:13 -0800

csiph-web