# Example 10 -- Geographical map using fancy map projection
# Note: the map projection is done with the 'proj' program,
# not part of Gri.
#
# Contributed 6 May 1996 by J. Witte <jwitte@phys.ocean.dal.ca>.

\head = "laea projection of 1990 NOx aircraft emissions at 9km"
\world = "/users/dek/kelley/data/Coastline/world1.dat"
\nox = "example.dat"

# Convert world map by first transforming coordinates ...
system proj +proj=laea \
    +over \
    +ellips=clrk66 \
    +lon_0=250 \
    +lat_0=90 \
    -m 1:10000000 \
    -f '%.4f' \
    < \world > tmp
# ... and then fixing the -999 values (used to indicate
# missing data at the ends of isolated coastline segments,
# for example around islands).
system sed -e s/*/-999/g < tmp > tmp2

# Convert coordinates of NOx emission trajectories, stored
# in first two columns.  Note that other columns in the
# file are retained by 'proj', as are comment lines.
system proj +proj=laea \
    +over \
    +ellips=clrk66 \
    +lon_0=250 \
    +lat_0=90 \
    -m 1:10000000 \
    -f '%.4f' \
    < \nox > airnox

open "gawk  'NR>1 && $5<50 {print($1,$2,$5)}' airnox |"
read columns x y z
set clip on
set x margin 3
set x size 14
set y margin 6
set y size 14

set x axis -0.6376 0.6326
set y axis -0.6353 0.558

set x name ""
set y name ""
draw axes frame

z /=50				# scale
set symbol size 0.15
draw symbol filledbox color hue z

draw label "\head" centered at \
    {rpn ..xmargin.. ..xsize.. 2 / +} \
    {rpn ..ymargin.. ..ysize.. + "M" ascent 2 . +} \
    cm

# Draw palette
set image range 0 50
set x format %g
set image colorscale hsb 0 1 1 0.0 hsb 1 1 1 50.0
draw image palette left 0 right 50 increment 5 \
	box {rpn ..xmargin..} {rpn ..ymargin.. ..ysize.. + 2 +}\
	{rpn ..xmargin.. ..xsize.. +} {rpn ..ymargin.. ..ysize.. + 2.5 +}

close
system rm -f airnox

# Draw coastline
open tmp2
set missing value -999
read columns x y
set clip on
set x margin 3
set x size 14
set y margin 6
set y size 14

set x axis -0.6376 0.6326
set y axis -0.6353 0.558
draw axes frame
close
set line width rapidograph 1	# fairly thick curve
draw curve
system rm -f tmp tmp2