! Example of curve filling with semi-transparency.
! Author: Francois Tonneau

! *Because this figure involves semi-transparent elements, it must be compiled
! with the -cairo option:*

! gle -cairo -d pdf fill.gle

! Not including this option will result in compilation failure.

size 12 9

set font texcmr

amove 1.5 1.5
begin graph
    size 9 6
    fullsize
    xaxis min 1700 max 1780 dticks 20 hei 0.3 grid color gray20
    yaxis min 0 max 200 dticks 20 hei 0.3 grid color gray20
    side color gray70
    labels color black dist 0.2
    ylabels off
    y2labels on

    data "fill-ft.dat" d1=c1,c2 d2=c3,c4

    ! We plot our data sets with Savitsky-Golay smoothed curves ('svg_smooth')
    ! and semi-transparent hues. The rgba255() function accepts four channel
    ! values in the 0-255 range: red, green, blue, and alpha/transparency.

    d1 svg_smooth line color rgba255(213,162,83,200) lwidth 0.05
    d2 svg_smooth line color rgba255(187,89,105,200) lwidth 0.05

    ! GLE can fill areas between an axis and a dataset or between different
    ! datasets. Also, filling can be clipped between minimal and maximal values.
    ! Here we add two semi-transparent fills to the plot, one to the left of
    ! x = 1754 and the other to the right; 1754 is where the curves of the
    ! d1 and d2 datasets cross.

    light$  = rgba255(247, 218, 215, 180)
    medium$ = rgba255(231, 217, 181, 180)

    fill d1,d2 color light$  xmin 1700 xmax 1754
    fill d1,d2 color medium$ xmin 1754 xmax 1780
end graph

! We add labels to the plot:

set font texcmti hei 0.325

amove 4.4 4
write "Balance against"

! Because the 'write' command cannot deal with multi-line labels, for our next
! label we employ a 'begin text ... end text' block:

amove 8.80 5.35
begin text
    Balance in
    favour of
    England.
end text

set font texcmb hei 0.3

! All the other labels are inserted in 'begin box ... end box' blocks to give
! the labels a rectangular white background. The 'add' option specifies the
! amount of padding between the text and the border of the box; 'nobox'
! means that the border will not be actually drawn:

amove 3.6 4.7
begin box add 0.05 nobox fill white
    write "Imports"
end box

amove 4.8 3.0
begin box add 0.05 nobox fill white
    write "Exports"
end box

set font texcmb hei 0.3 just lc

amove 1.9 7.2
begin box add 0.05 nobox fill white
    write "Exports and Imports to and from"
end box
rmove 0 -0.3
begin box add 0.05 nobox fill white
    write "DENMARK & NORWAY"
end box
rmove 0 -0.3
begin box add 0.05 nobox fill white
    write "from 1700 to 1780."
end box

set font texcmr hei 0.25 just lc

amove 3.4 1.8
begin box add 0.10 nobox fill white
    write "Bottom line in years, right hand line divided into L10,000 each."
end box

! Done. We have learned about curve filling, rgba255() transparency, 'begin
! text ... end text' blocks, and 'begin box ... end box' blocks.