# GMTLIST

NAME
SYNOPSIS
DESCRIPTION
OPTIONS
EXAMPLES
SEE ALSO
REFERENCES

## NAME

gmtlist − A data-extractor for <legid>.gmt files

## SYNOPSIS

gmtlist leg-ids [ −C correctionfile ] [ −Da startdate ] [ −Db stopdate ] [ −F flags ] [ −G ] [ −H[i][nrec] ] [ −R west/east/south/north[r] ] [ −Sa startdist ] [ −Sb stopdist ] [ −V ] [ −W weight ] [ −bo[s|S|d|D[ncol]|c[var1/...]] ]

## 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 arguments

| −C |  | Apply crossover Corrections to the data. If no correction file is given, gmtlist reads the default correction 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 G, M, or T is substituted for g, m, t, only records that have that combination of data are written out. If s is followed by c (calendar), 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.
| −R |  | west, east, south, and north specify the Region of interest, and you may specify them in decimal degrees or in [+-]dd:mm[:ss.xxx][W|E|S|N] format. Append r if lower left and upper right map coordinates are given instead of w/e/s/n. The two shorthands −Rg and −Rd stand for global domain (0/360 and -180/+180 in longitude respectively, with -90/+90 in latitude). Alternatively, specify the name of an existing grid file and the −R settings (and grid spacing, if applicable) are copied from the grid.
| −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 calendar 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:

gmtlist ‘cat gmt.list‘ −Fxyg −R-40/-30/25/35 −b > allgrav.xyg

## SEE ALSO

GMT(1), x_system(1)

## REFERENCES

Wessel, P., and W. H. F. Smith, 2009, The Generic Mapping Tools (GMT) version 4.5.0 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.