#!/bin/csh -f

if ($#argv < 1) then
        echo
        echo " Usage: makeFracGrid.com xyzfile" 
        echo " example "
        echo "  makeFracGrid.com ship_ratio_world.xyz"
        exit 1
endif
 
set infile = $1

set range = -R0/360/-72/72
set displayInc = -I0.25/0.2
set filterInc = -I0.1
set clipLimit = 0.16


rm -f criticalCount.grd	criticalCount.xyz 
rm -f criticalFraction.grd filteredCriticalCount.grd
rm -f totalCount.grd filteredTotalCount.grd clippedFilteredTotalCount.grd
rm -f tmp.grd


# pull out critical ratios, i.e. slope/critical > 1.0

awk '{if ($3 > 1.00) print $1,$2,$3}' < $infile > criticalCount.xyz


# count number of pings per node.
#
# Note the -An and the use of a smaller -I than the display -I
#
# The key thought is we really want count of ratio>1 at each node, 
# not the value of ratio at node!

xyz2grd -An -V -N0 $range $filterInc $infile 		-GtotalCount.grd
xyz2grd -An -V -N0 $range $filterInc criticalCount.xyz	-GcriticalCount.grd

# filter the count to smooth out artificats and just because...

grdfilter $range $filterInc -V -D3 -Fg60 totalCount.grd -GfilteredTotalCount.grd
grdfilter $range $filterInc -V -D3 -Fg60 criticalCount.grd -GfilteredCriticalCount.grd

# Clip filtered count to NaN if less than clipLimit.
#
# this grdmath says 
#	if input < limit place on stack a 0 else 1, 
#	replace any 0 with Nan, 
# 	now we have either a 1 or NAN on stack
#	a MUL with original data gives input data 
#	except with clipped locations replaced by NAN

grdmath filteredTotalCount.grd DUP $clipLimit GT 0 NAN MUL = clippedFilteredTotalCount.grd

# Calculate ratio of filtered critical and total count

grdmath filteredCriticalCount.grd clippedFilteredTotalCount.grd DIV = criticalFraction.grd

# surface, grid and filter at display grid size.

grd2xyz criticalFraction.grd -V -L -S > criticalFraction.xyz
surface criticalFraction.xyz $range $displayInc -V -L -Ll0.0 -Lu1.0 -T.25 -Gtmp.grd

chmod a+rw *
grdfilter tmp.grd $range $displayInc -V -D3 -Fm60 -Gfrac.grd

exit

rm -f criticalCount.grd	criticalCount.xyz 
rm -f criticalFraction.grd filteredCriticalCount.grd
rm -f totalCount.grd filteredTotalCount.grd clippedFilteredTotalCount.grd
rm -f tmp.grd