NAME
gmtlist - A data-extractor for <legid>.gmt files
SYNOPSIS
gmtlist leg-ids [ -Ccorrectionfile ] [ -Dastartdate ] [
-Dbstopdate ] [ -Fflags ] [ -G ] [ -H ] [
-Rwest/east/south/north ] [ -Sastartdist ] [ -Sbstopdist ] [
-V ] [ -Wweight ] [ -b ]
DESCRIPTION
gmtlist reads <legid>.gmt files and produces an ASCII [or
binary] table. The <legid>.gmt files contain time(s),
latitude(y), longitude(x), gravity(g/G), magnetics(m/M), and
bathymetry(t/T), and the user may extract any combination of
these 6 parameters + distance(d), heading (h), velocity (v),
and weight (w, see -W). A sub-section can be specified by
passing time- or distance-intervals along track or by
selecting a region.
leg-ids
Can be one or more cruisenames. To give a list of
names, use `cat list_of_legs`.
OPTIONS
No space between the option flag and the associated argu-
ments
-C Apply crossover Corrections to the data. If no correc-
tion file is given, gmtlist reads the default correc-
tion file. (See XSYSTEM for how to set up your own
correction file)
-Da Do not list data collected before startdate
(mm/dd/yyyy/hh:mm) [Default is first day].
-Db Do not list data collected after stopdate
(mm/dd/yyyy/hh:mm). [Default is last day].
-F Can be any combination of syxgmtdhv to indicate the
desired output data. The data will appear in the order
indicated by flags. If GMT is substituted for gmt, only
records that have that combination of data are written
out. If s is followed by c (calender), then
yyyy/mm/dd/hh/mm/ss is written out, if s is followed by
j (julian), then yyyy/jd/hh/mm/ss is written out.
Default is seconds from start of year.
-G Force Geographical longitudes (-180/+180) rather than
geodetic (0-360) [Default].
-H Issue a header record with names for each data field.
-Sa Do not list data that are less than startdist km along
track from port of departure. [Default is 0].
-Sb Do not list data that are more than stopdist km along
track from port of departure. [Default is length of
track].
-V Selects verbose mode, which will send progress reports
to stderr [Default runs "silently"].
-W Set the weight for these data. Weight output option
must be set in -F. This is useful if the data are to
be processed with the weighted averaging techniques
offered by blockmean, blockmedian, and blockmode.
-b Selects binary output mode (in double precision)
[Default is ASCII]. -H is ignored if -b is selected.
Julian and calender dates are not supported for binary
time output (i.e., you get seconds from start of year).
EXAMPLES
To get a (distance, heading, crossover-corrected gravity,
bathymetry) listing from c2104.gmt, starting at June 3 1971
20:45 and ending at distance = 5000 km, use the following
command:
gmtlist c2104 -Da6/3/1971/20:45 -Sb5000 -Fdhgt -C > myfile
To make input for blockmean and surface using all the
cruises listed in the file gmt.list, but only the data that
are inside the specified area, and make output binary, try:
gmtlist `cat gmt.list` -Fxyg -R-40/-30/25/35 -b >
allgrav.xyg
SEE ALSO
gmt(l), xsystem(l)
REFERENCES
Wessel, P., and W. H. F. Smith, 1999, The Generic Mapping
Tools (GMT) version 3.2 Technical Reference & Cookbook,
SOEST/NOAA.
Wessel, P., and W. H. F. Smith, 1998, New, Improved Version
of Generic Mapping Tools Released, EOS Trans., AGU, 79 (47),
p. 579.
Wessel, P., and W. H. F. Smith, 1995, New Version of the
Generic Mapping Tools Released, EOS Trans., AGU, 76 (33), p.
329.
Wessel, P., and W. H. F. Smith, 1995, New Version of the
Generic Mapping Tools Released,
http://www.agu.org/eos_elec/95154e.html, Copyright 1995 by
the American Geophysical Union.
Wessel, P., and W. H. F. Smith, 1991, Free Software Helps
Map and Display Data, EOS Trans., AGU, 72 (41), p. 441.