# set terminal pngcairo  transparent enhanced font "arial,10" fontscale 1.0 size 600, 400 
# set output 'stringvar.6.png'
set key title "file(i) = sprintf(\"%1d.dat\",i); N=2; M=3" center
set key fixed left top vertical Left reverse enhanced autotitle nobox
set key noinvert samplen 4 spacing 1 width 25 height 0 
set style increment default
set title "String-valued functions to generate datafile names" 
set xrange [ * : * ] noreverse writeback
set x2range [ * : * ] noreverse writeback
set yrange [ * : * ] noreverse writeback
set y2range [ * : * ] noreverse writeback
set zrange [ * : * ] noreverse writeback
set cbrange [ * : * ] noreverse writeback
set rrange [ * : * ] noreverse writeback
file(i) = sprintf("%1d.dat",i)
iswindows = 0
beg = 2
end = 4
foo = "Apostrophes inside words don't matter"
haystack = "Thu Nov 15 12:12:38 PST 2018"
needle = ":"
S = 14
N = 2
M = 3
## Last datafile plotted: "3.dat"
plot 5*sin(x)/x, file(N), file(M)