I am a bit confused, I have the same gnuplot script that works under
Version 4.6 patchlevel 4 Build System: Linux x86_64
but not under
Version 4.6 patchlevel 5 Build System: MS-Windows 32 bit
the script file is
clear
set terminal epslatex size 20cm,14cm
set output 'mwe.tex'
set style data points
set style line 101 lc rgb "black" lw 2 pt 1 ps 2
set grid
set xlabel 'xlabel'
set ylabel 'ylabel'
xmin= -0.2
xmax= 0.7
set xrange [xmin:xmax]
set key below
plot "<echo '0.408 270.7'" with points ls 101 notitle,\
Does the command "<echo somehow not work under Windows?
The error I get with Windows is 'skipping unreadable file "
The < pipes the following command through a shell (see help special-filenames). The command itself is mostly system-dependent and not part of gnuplot (in this case the echo).
If you want a portable way to specify a single point, you can set an empty label and use the point option:
set style line 101 lc rgb "black" lw 2 pt 1 ps 2
set label at 0.408, 270.7 "" point ls 101
Note, that this works only if you also plot other stuff, since the label is set only if the plot command is invoked.