gnuplot-info

[Gnuplot-info] information about a point in scatter

[antong <ant...@gm...>]

Hi all, 

I have the following problem and I hope you can help me with it:

I create 2D scatter plots from a text file, which works fine. But now I want
to retrieve additional information about a specific data point. For example,
I plot the weights of different design alternatives against the production
costs. Now I want to know the number of the design with the lowest costs and
the highest weight. Plotting the design numbers as labels is not really an
option, because their are to many points which makes the labels unreadable. 

I thought that it might be possible to retrieve data from a point by moving
the mouse over that point. But I'm not sure if that is possible at all. If
not or if you have other ideas, pleas let me know!

Thanks for your help.

Regards, 

Anton

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Re: [Gnuplot-info] information about a point in scatter

[carminat <car...@dm...>]

I had the same problem (and asked the same question some time ago "in gnuplot
in action" forum).
Although I do not really have The Answer, I can tell what I did in my case,
which I presume is quite typical.

The data I was interested in were more or less on a extremal curve; I firs
did some transform to stighten the curve, and then I  excluded  data which
were far away from this locus  (you can do this as follows: use the "set
table" option together the ternary operator ? to print into a file numbers
of data lines which are near the curve, then use this information to extract
these lines from your dataset).

Thus you are left with a much smaller file, and plotting with labels is more
reasonable (three digits labels are not so terrible). To do it in the best
way, you should try to apply some transform so that the "curve" of
interesting data is plotted as a vertical line (so that labels do not
overlap).

Of course, I would love to have "invisible labels", which are displayed on
mouse clicks!
 


antong wrote:
> 
> I create 2D scatter plots from a text file, which works fine. But now I
> want to retrieve additional information about a specific data point. 
> [...]
> I thought that it might be possible to retrieve data from a point by
> moving the mouse over that point. But I'm not sure if that is possible at
> all. If not or if you have other ideas, pleas let me know!
> 
> Anton
> 
> 

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Re: [Gnuplot-info] information about a point in scatter

[Anton G. <ant...@gm...>]

Thanks for your reply! I found your topic on the 'gnuplot in action' forum
and we have indeed the same problem. The answer they gave is however very
clear ('I don't think gnuplot currently has this ability. You might want to
suggest it though on the gnuplot maintainers mailing list.')

Fitting a curve through the data doesn't really work for me, because the
data is not on or close to a single curve or surface and I am not always
interested in the same data points. However, the idea to extract data from
the original database can maybe help me further.

Some other ideas I had:

   - creating a 3D scatter, which is plotted in 2D. The third axis can be
   used to store extra information, which can be derived by rotating the plot.
   - maybe it is possible to use the coordinates of a mouse click to create
   a new plot in which the data point closest to those coordinates is labeled.
   I haven't tried this option yet, but I think it should be possible.

Feel free to send me other ideas, thoughts or experiences with this problem!

Anton



2012/3/15 carminat <car...@dm...>

>
> I had the same problem (and asked the same question some time ago "in
> gnuplot
> in action" forum).
> Although I do not really have The Answer, I can tell what I did in my case,
> which I presume is quite typical.
>
> The data I was interested in were more or less on a extremal curve; I firs
> did some transform to stighten the curve, and then I  excluded  data which
> were far away from this locus  (you can do this as follows: use the "set
> table" option together the ternary operator ? to print into a file numbers
> of data lines which are near the curve, then use this information to
> extract
> these lines from your dataset).
>
> Thus you are left with a much smaller file, and plotting with labels is
> more
> reasonable (three digits labels are not so terrible). To do it in the best
> way, you should try to apply some transform so that the "curve" of
> interesting data is plotted as a vertical line (so that labels do not
> overlap).
>
> Of course, I would love to have "invisible labels", which are displayed on
> mouse clicks!
>
>
>
> antong wrote:
> >
> > I create 2D scatter plots from a text file, which works fine. But now I
> > want to retrieve additional information about a specific data point.
> > [...]
> > I thought that it might be possible to retrieve data from a point by
> > moving the mouse over that point. But I'm not sure if that is possible at
> > all. If not or if you have other ideas, pleas let me know!
> >
> > Anton
> >
> >
>
> --
> View this message in context:
> http://old.nabble.com/information-about-a-point-in-scatter-tp33478029p33508157.html
> Sent from the Gnuplot - User mailing list archive at Nabble.com.
>
>
>
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