define partition      ! This allocates space for the three plots
set \0 gx2 - gx1      ! \0 is the width of the entire plot in device coords
set \1 gy2 - gy1      ! \1 is the height of the entire plot in device coords
set \2 \0 + \1        ! \2 is an average, ok for both portrait and landscape
set \2 \2 * 0.17      ! \2 is now the height of the halftone plot
set \5 gx1 + gx2
set \5 \5 * 0.5       ! \5 is the x center of the plot
set \0 \0 * 0.05      ! \0 is a gap in x between the 3d and line plot
set \1 \1 * 0.1       ! \1 is a gap in y between halftone and others
set \6 gx1            ! save gx1
set \7 gx2            ! save gx2
set \8 gy1 + \2       ! save gy1
set \9 gy2            ! save gy2
end

define plot1          ! This makes the line plot
set gx1 \5 + \0       ! set gx1 to gap width right of center
set gx2 \7            ! set gx2 to right boundary
set gy1 \8 + \1       ! set gy1 to gap width above halftone plot
set gy2 \9            ! set gy2 to top boundary
xcolumn -100          ! create abcissa for plot
ycolumn 25            ! extract center cut through data array for y
limits                ! set plot limits
box 111 112           ! put a box with plain labels around the area
connect               ! connect the curve
end

define plot2          ! This makes the 3d-plot
set gx1 \6            ! set gx1 to left boundary
set gx2 \5 - \0       ! set gx2 to gap width left of center
set gy1 \8 + \1       ! set gy1 to gap width above halftone plot
set gy2 \9            ! set gy2 to top boundary
3dplot 40 30 0.5      ! 3d-plot, altitude = 40, azimuth = 30, datamax ~ 0.5
end

define plot3          ! This makes the halftone and contour plot (2x1 aspect)
set gx1 \5 - \2       ! set gx1 to one height left of center
set gx2 \5 + \2       ! set gx2 to one height right of center
set gy1 \8 - \2       ! set gy1 to bottom boundary
set gy2 \8            ! set gy2 to one height above bottom
contour 1 0           ! draw one contour level at data = 0
halftone -0.1 0.6     ! make halftone plot: -0.1 = black, +0.6 = white
limits 0 100 0 50     ! set limits of plot
box                   ! put a box around the area
end