Gnuplot : Using a stats output as a data point

Question

I have three data files each with a matrix; I use stats to find the maximum value in the matrix for each file and it is displayed correctly. I need to use those three maximum values as data points and plot them so as to have points on my plot as (1.0, A_max), (2.0, B_max) and (3.0, C_max) where A_max is the maximum value calculated using stats from first data file, B_max from second and C_max from third. Here is how my gp file looks like :

    set terminal epslatex size 3.5,2.62 color colortext
    set output 'data.tex'
    set xlabel '$x$'
    set ylabel '$y$'

    stats 'dataA.txt' matrix name "A"
    show variables A_
    stats 'dataB.txt' matrix name "B"
    show variables B_
    stats 'dataC.txt' matrix name "C"
    show variables C_

    plot '-' w p, '-' w p, '-' w p
    1.0 A_max
    e   
    2.0 B_max
    e
    3.0 C_max
    e

The plot I get, looks like below.

Data plot

Clearly, it is taking x-axis as 0 and the points I intend for my x-axis corresponding to y. Not sure what I am missing, probably how to read the stats variable. Any help will be appreciated.

Christoph Christoph · Accepted Answer · 2018-03-16T19:02:14

Inline data, like you are using, is used as-is without any variable replacement. Use set print $data to print data to the named data block $data:

set print $data
stats 'dataA.txt' matrix name "A"
print sprintf("%e A", A_max)
stats 'dataB.txt' matrix name "B"
print sprintf("%e B", B_max)
stats 'dataC.txt' matrix name "C"
print sprintf("%e C", C_max)
plot $data using 0:1:xticlabel(2) w p notitle

or, with more automation:

set print $data
do for [f in "A B C"]{
    stats 'data'.f.'.txt' matrix name f
    print sprintf("%e %s", value(f.'_max), f)
}
plot $data using 0:1:xticlabel(2) w p notitle

Gnuplot : Using a stats output as a data point

1 Answers