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Diffstat (limited to 'ipl/gpacks/tiger/tgrtrack.icn')
| -rw-r--r-- | ipl/gpacks/tiger/tgrtrack.icn | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/ipl/gpacks/tiger/tgrtrack.icn b/ipl/gpacks/tiger/tgrtrack.icn new file mode 100644 index 0000000..07a25f2 --- /dev/null +++ b/ipl/gpacks/tiger/tgrtrack.icn @@ -0,0 +1,168 @@ +############################################################################ +# +# File: tgrtrack.icn +# +# Subject: Program to translate "track log" files into TIGER chains +# +# Author: William S. Evans and Gregg M. Townsend +# +# Date: June 9, 2000 +# +############################################################################ +# +# tgrtrack reads a fixed field length file containing track data from +# a GPS receiver and outputs a "line chain" (.lch) format file (see +# tgrprep) that can then be viewed using tgrmap. +# +# Usage: tgrtrack file +# +# Input is a text file of coordinates such as those from a GPS +# receiver. Lines ending with two decimal values are interpreted +# as specifying latitude and longitude in that order. +# Lines without data indicate breaks between paths. +# +# Output is a line chain file +# +############################################################################ +# +# Links: numbers, strings +# +############################################################################ + +link numbers +link strings + +global deltas +global curlon, curlat +global maxlon, minlon, maxlat, minlat + +procedure main(args) + local n, trackfile + + *args = 1 | stop("usage: ", &progname, " GPStrackfile") + trackfile := open(args[1]) | stop("can't open ", args[1]) + n := llrange(trackfile) + write(" ", rz(convertLon(minlon)), rz(convertLat(maxlat))) + write(" ", rz(convertLon(maxlon)), rz(convertLat(minlat))) + writeLCH(trackfile) + return +end + +procedure convertLat(n) +# convert latitude from decimal degrees to fraction of semicircle +# south of North Pole, as 0000000 to 9999999. + static m + initial m := 9999999 / 180.0 + return round(m * (90.0 - n)) +end + +procedure convertLon(n) +# convert longitude to fraction of circle east of Greenwich, +# as 0000000 to 9999999. + static m + initial m := 9999999 / 360.0 + + n := real(n) + if n < 0 then + n +:= 360.0 + return round(m * n) +end + + +procedure writeLCH(trackfile) + local x, y, line, n, trackPts, dim, startlon, startlat, lon, lat, w + + n := 1 + trackPts := 0 + deltas := "" + + seek(trackfile, 1) | fail + repeat { + line := read(trackfile) | "stop" + every put(w := [], words(line)) + if (lat := real(w[-2])) & (lon := real(w[-1])) & + (-90. <= lat <= 90.) & (-180. <= lon <= 180.) then { + y := convertLat(lat) + x := convertLon(lon) + if (trackPts = 0) then { # starting a new track + deltas := "" + startlon := minlon := maxlon := curlon := x + startlat := minlat := maxlat := curlat := y + } + else { + drawto(x, y) + } + trackPts +:= 1 + } + else { + if trackPts >= 2 then { + dim := startlon - minlon + dim <:= maxlon - startlon + dim <:= startlat - minlat + dim <:= maxlat - startlat + dim >:= 9999 + write("T000|GPS Track ", n, "|", right(dim, 4), + rz(startlon), rz(startlat), deltas) + n +:= 1 + } + trackPts := 0 + } + if w[1] == "stop" then break + } + return +end + +procedure drawto(lon, lat) + local dlon, dlat + + dlon := lon - curlon + dlat := lat - curlat + + if abs(dlon | dlat) >= 5000 then { + drawto(curlon + dlon / 2, curlat + dlat / 2) + drawto(lon, lat) + } + else { + deltas ||:= rz(dlon + 5000, 4) + deltas ||:= rz(dlat + 5000, 4) + curlon := lon + curlat := lat + minlon >:= lon + maxlon <:= lon + minlat >:= lat + maxlat <:= lat + } + return +end + + +procedure rz(v, n) +# right-justify value in n digits with zero fill + /n := 7 + return right(v, n, "0") +end + + +procedure llrange(f) +# scan f to set min/max lon/lat, returning record count + local line, n, lon, lat, w + + minlon := +180.0 + maxlon := -180.0 + minlat := +90.0 + maxlat := -90.0 + n := 0 + + seek(f, 1) + while line := read(f) do line ? { + every put(w := [], words(line)) + if (lat := real(w[-2])) & (lon := real(w[-1])) & + (-90. <= lat <= 90.) & (-180. <= lon <= 180.) then { + minlon >:= lon + maxlon <:= lon + minlat >:= lat + maxlat <:= lat + } + } + return n +end |