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

Groups > comp.graphics.apps.gnuplot > #3913

Re: Missing points in multi line plot not being omitted

Show all headers | View raw

On 10.03.2018 12:09, Chris Elvidge wrote:
> On 10/03/2018 09:57 am, Jörg Buchholz wrote:
>> On 10.03.2018 08:18, Ethan A Merritt wrote:
>>> Jörg Buchholz wrote:
>>>
>>>> On 09.03.2018 19:48, Marius Schamschula wrote:
>>>>
>>>>>
>>>>> FYI, I'm using version 5.2 patchlevel 2 under FreeBSD, so indeed
>>>>> there should not be any quotes around the NaN
>>>>>
>>>>> Dealing with single points is easy: add a marker. My problem is
>>>>> having lines where they shouldn't be.
>>>>>
>>>> I have compiled the 5.2.2 Version and it confuse me.
>>>>
>>>> set style data linespoints
>>>> set datafile missing NaN
>>>> plot '-' u 1:2
>>>> input data ('e' ends) > 1 10
>>>> input data ('e' ends) > 2 20
>>>> input data ('e' ends) > 3 NaN
>>>> input data ('e' ends) > 4 40
>>>> input data ('e' ends) > 5 50
>>>> input data ('e' ends) > e
>>>>
>>>> There is no gap in the output.
>>>
>>> Correct. There is no gap because the NaN point is treated as missing.
>>>  From the docs under "help missing"
>>>
>>>     "invalid data causes a gap in a line drawn through sequential
>>>      data points; missing data does not."
>>>
>>>
>>>> unset datafile missing NaN
>>>> plot '-' u 1:2
>>>> input data ('e' ends) > 1 10
>>>> input data ('e' ends) > 2 20
>>>> input data ('e' ends) > 3 NaN
>>>> input data ('e' ends) > 4 40
>>>> input data ('e' ends) > 5 50
>>>> input data ('e' ends) > e
>>>>
>>>> There is a gap between 2 - 4 in the output.
>>>
>>> Yes, because now the point is not "missing".  It is "invalid".
>>>
>>>> In the 5.2 Documentation there are some examples for the "set datafile
>>>> missing option". Only the examples with "NaN" direct in the data gives
>>>> a gap.
>>>
>>> Correct.
>>>
>>>> So can you put a "NaN" into your data?
>>>>
>>>> IMHO the 5.0 Version works nicer, or more than I expected. Or is it a
>>>> bug?
>>>
>>>> Jörg
>>>
>>> Perhaps a misunderstanding.   Let me try re-phrasing...
>>>
>>> "Missing" data acts as if no entry at that x coordinate was present
>>> in the data file at all, so it has no effect on the line being drawn.
>>>
>>> A gap in the line indicates that data at that x coordinate was present,
>>> but invalid.
>>>
>>> The special command "set datafile missing NaN" tells the program
>>> to treat invalid data as if it were missing (no gap).
>>>
>>>     Ethan
>>>
>> Thanks for your explanation. So it was a misunderstanding. But the
>> behave from gnuplot 5.0 is nice and easy to handle.
>>
>> So for gnuplot 5.2 the only solution is something like "sed -i
>> 's/?/NaN/g' datafile.dat" before plotting the data or in a pipe?
>>
>> Jörg
>>
> 
> Or use "set datafile missing ?" (or "set datafile missing '?'") ??

No, this don't give a gap.

> From the manual: There is no default character for missing, but in many
> cases any non-parsible string of characters found where a numerical
> value is expected will be treated as missing data.
> 
> So will a "?" in the data be treated as missing, even without the "set
> datafile missing" line. plot '-' using 1:($2) suggests it will.

Yes, that works. So, if I understand the problem from Marius correct, he
must only disable the "set datafile missing ..." command and write the
Y-column like "($3)".

I put his data example into the file "wind.data" and the following gives
 a line with gaps in the "Gust".

set grid
gnuplot> set time
gnuplot> set xdata time
gnuplot> set timefmt "%Y-%m-%d:%H:%M:%S"
gnuplot> unset timestamp
plot 'wind.data' u 1:($2) t 'Wind' w lines lt rgb "blue", '' u 1:($3) t
'Gust' w lines

gnuplot Version 5.2 patchlevel 2

And the good thing for me: I have learned how to plot data with a gap in
the line with gnuplot 5.2


Jörg

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

Thread

Missing points in multi line plot not being omitted Marius Schamschula <mschamschula@gmail.com> - 2018-03-07 10:33 -0800
  Re: Missing points in multi line plot not being omitted Jörg Buchholz <bookwood4new@freenet.de> - 2018-03-08 11:39 +0100
    Re: Missing points in multi line plot not being omitted Marius Schamschula <mschamschula@gmail.com> - 2018-03-08 06:35 -0800
      Re: Missing points in multi line plot not being omitted Chris Elvidge <chris@mshome.net> - 2018-03-08 16:24 +0000
      Re: Missing points in multi line plot not being omitted Jörg Buchholz <bookwood4new@freenet.de> - 2018-03-08 20:10 +0100
        Re: Missing points in multi line plot not being omitted Ethan Merritt <sfeam@users.sf.net> - 2018-03-08 19:54 +0000
        Re: Missing points in multi line plot not being omitted Chris Elvidge <chris@mshome.net> - 2018-03-08 20:40 +0000
  Re: Missing points in multi line plot not being omitted Marius Schamschula <mschamschula@gmail.com> - 2018-03-09 10:48 -0800
    Re: Missing points in multi line plot not being omitted Jörg Buchholz <bookwood4new@freenet.de> - 2018-03-09 21:09 +0100
      Re: Missing points in multi line plot not being omitted Ethan A Merritt <EAMerritt@gmail.com> - 2018-03-09 23:18 -0800
        Re: Missing points in multi line plot not being omitted Jörg Buchholz <bookwood4new@freenet.de> - 2018-03-10 10:57 +0100
          Re: Missing points in multi line plot not being omitted Chris Elvidge <chris@mshome.net> - 2018-03-10 11:09 +0000
            Re: Missing points in multi line plot not being omitted Jörg Buchholz <bookwood4new@freenet.de> - 2018-03-10 17:40 +0100
              Re: Missing points in multi line plot not being omitted Chris Elvidge <chris@mshome.net> - 2018-03-10 17:01 +0000
                Re: Missing points in multi line plot not being omitted Jörg Buchholz <bookwood4new@freenet.de> - 2018-03-11 09:47 +0100
                Re: Missing points in multi line plot not being omitted Chris Elvidge <chris@mshome.net> - 2018-03-11 10:41 +0000

csiph-web