unset border
unset tics
unset key
H = 1.2
RN = 25
set xrange [-1:21]
set term post enh font "Courier,11" size 7.2,7.2 port color
set out "marks_ps.eps"
plot for [ i= 0:9] for [j = 0:RN-1] '+' u (2.3*i):(H*(RN-j))  ps 1.8, \
     for [ i = 0:9] for [j = 0:RN-1] \
     '+' u (2.3*i-1):(H*(RN-j)):(sprintf("%d",RN*i+j+1)) w labels
!convert marks_ps.eps marks_ps.png

# Postscript では，225種類の記号があります．
# 色は，原則9種類の循環（70-74, 144-149, 219-224は例外）
# 記号は，75種類の循環