Reusing inline data in gnuplot

Question

Does anyone know how I can reuse inline data in Gnuplot, I've been googling it and can't find nothing everything suggests to input the data gain? Basically reuse the '-' file.

Answer 1

since I stumbled over this old question via Google...

There are two ways to having "inline data" (data in the gnuplot file):

1. the special filename '-', which reads the lines immediately following the plot command. This data can only be used once.
2. named datablocks with here documents, which can be reused:

$Data << EOD
0 0 0
1 1 1
2 2 4
3 3 9
4 4 16
EOD

plot $Data using 1:2 title 'linear' with linespoints, \
     $Data using 1:3 title 'quadratic' with linespoints

See http://gnuplot.info/docs_5.5/loc3521.html

Answer 2

Using blockdata is most useful see Gnuplot: Histogram plots with inline data

However: Reading gnuplot embedded help:

gnuplot> help plot  datafile  special-filenames

states:

... The special filename '-' specifies that the data are inline; ... If you use '-' ... you may need to enter the data more than once. ... A blank filename ('') specifies that the previous filename should be reused. ... (If you use both '-' and '' on the same plot command, you'll need to have two sets of inline data, as in the example above.)

so you can do:

gnuplot> plot '-' using 1:2, '' using 1:3
input data ('e' ends) >

and then paste the same data twice:

      0.000              0              0    
      0.001            104             51
      0.002            202            101
      0.003            298            148
      0.0031           290            149
      0.004            289            201
      0.0041           291            209
      0.005            310            250
      0.010            311            260
      0.020            280            240
e
input data ('e' ends) > input data ('e' ends) > input data ('e' ends) > input data ('e' ends) > input data ('e' ends) > input data ('e' ends) > input data ('e' ends) > input data ('e' ends) > input data ('e' ends) > input data ('e' ends) > input data ('e' ends) >
      0.000              0              0    
      0.001            104             51
      0.002            202            101
      0.003            298            148
      0.0031           290            149
      0.004            289            201
      0.0041           291            209
      0.005            310            250
      0.010            311            260
      0.020            280            240
e
input data ('e' ends) > input data ('e' ends) > input data ('e' ends) > input data ('e' ends) > input data ('e' ends) > input data ('e' ends) > input data ('e' ends) > input data ('e' ends) > input data ('e' ends) > input data ('e' ends) >
gnuplot> 

output graphic plot

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environment under test:

linuxuser@ubuntu:~$ uname -a
Linux ubuntu 4.15.0-74-generic #84-Ubuntu SMP Thu Dec 19 08:06:00 UTC 2019 i686 i686 i686 GNU/Linux

linuxuser@ubuntu:~$ gnuplot -V
gnuplot 5.2 patchlevel 2

Answer 3

in place of a bare replot, you can use refresh if you're using gnuplot 4.3 or newer. If you actually want to add more data to be plotted, I think you're out of luck.

e.g.

plot '-' u 1:2
 1 2
 2 3
 e
set label "Hello World!" at 1.5,2.5
refresh