Comments on: Equipotential lines

By: Elena

Elena — Wed, 08 Mar 2017 00:47:20 +0000

Hi, what can we do if we have already all values for x,y and the potencial and we want to input in gnuplot as equipotencial lines instead of “degradation” of the potencial?

Thanks

By: Alejandro

Alejandro — Thu, 15 Sep 2016 16:28:11 +0000

Exactly. Thanks!

By: hagen

hagen — Wed, 14 Sep 2016 10:51:54 +0000

I guess you mean something like this:

Fig. 3 Equipotential lines of a plate with electric charges with labels. The data was formated with "%.1f". (code to produce this figure)

If you specify the "%.1f" format before the set table command your data in equipotential_lines.txt will change and be cut after the first decimal place. That is the reason while it no longer looks smooth.

By: Alejandro

Alejandro — Tue, 13 Sep 2016 15:30:19 +0000

Several times I looked here for help and inspiration, but this is the second time (./../../attractive-plots/index.html) that I’m commenting to you. Great, great work Hagen.

Well, something curious. Try adding

set format x "%.1f"
set format y "%.1f"

to equipotential_lines2.gnu for example. These axes-aesthetic commands damage the generation of the equipotential lines points and “break” the smoothness of the equipotential lines!

Any idea to circumvent this issue?

Greetings from BA

By: hagen

hagen — Mon, 26 Jan 2015 08:05:30 +0000

Hi Dai,

another example of the plotting style labels can be found here:
./../../us-states-and-election-results/index.html

By: Dai

Dai — Thu, 22 Jan 2015 17:00:05 +0000

I think I’ve just figured out a way to answer my own question – I just have to reorgainise my data so that it looks like the table output in “equipotential_lines.txt” and use the plot function at the end of the example file.

By: Dai

Dai — Thu, 22 Jan 2015 16:32:22 +0000

Hi,

Is there a way of adding arbitrary text labels, say from a text file? I want to plot a series of height profiles for a gravity current at various time intervals, and label each profile with the corresponding time.

Thanks for your help.
Dai

By: hagen

hagen — Mon, 14 Apr 2014 07:12:24 +0000

Hi Wojtek,
interesting, what version of gnuplot do you running?
I use version 4.6 patchlevel 0 and everything works fine.

By: Wojtek

Wojtek — Fri, 11 Apr 2014 11:39:24 +0000

Alas, something seems to have changed in gnuplot, since now the labels(x,y) function produces error “stringcolumn() called from invalid context” whenever I try to use it. Unless I’m doing something wrong:)
Thanks for the article anyway!

By: Tojur

Tojur — Wed, 23 Oct 2013 05:26:38 +0000

The way you put the labels in the levels is by far the easiest and more direct solution to this problem. This can be done with a pm3d map/splot too. This was very helpful. Thank you very much