[gnuplot] make a multiplot (3 stacked plots)

Here is an example I made to generate a multiplot by gnuplot. I don’t want the 3 plots have space in between the x-axis. So the trick thing is: set the margin (r, l, t,b) very smaller,e.g. 0.01. Then the output looks “like” 3 stacked plots. You can modify it by 3 connected plots in a row (left, middle, right).

The plot is shown here:

The scripts is pasting here:
=========================
set terminal postscript
set output “data.ps”
unset key
NX=1; NY=3
DX=0.01; DY=0.01; SX=0.85; SY=0.25
set bmargin DX; set tmargin DX; set lmargin DY; set rmargin DY
## set the margin of each side of a plot as small as possible
## to connect each plot without space
set size SX*NX+DX*1.5,SY*NY+DY*1.8
set multiplot
##—— First Figure–bottom
set size SX,SY
set xrange [0:140]
set yrange [-0.9:0.9]
set ytic -0.6,0.3,0.6 ### from -0.6 to 0.6 with 0.3 interval
set origin DX,DY;
plot sin(x)
###——Second Figure—middle
set origin DX,DY+SY;
unset xtics
plot sin(x**2)
##——- Third Figure—-top
set origin DX,DY+SY*2
plot cos(x)
unset multiplot