x2sys_datalist(1) GMT x2sys_datalist(1)
NAME
x2sys_datalist - Extract content of track data files
SYNOPSIS
x2sys_datalist track(s) -TTAG [ -A ] [ -E ] [ -Fname1,name2,a| ] [
-I[list] ] [ -L[corrtable] ] [ -Rregion ] [ -S ] [ [ -V[level] ] [
-bobinary ] [ -donodata ] [ -hheaders ]
Note: No space is allowed between the option flag and the associated
arguments.
DESCRIPTION
x2sys_datalist reads one or more files and produces a single ASCII [or
binary] table. The files can be of any format, which must be described
and passed with the -T option. You may limit the output to a geo-
graphic region, and insist that the output from several files be sepa-
rated by a multiple segment header. Only the named data fields will be
output [Default selects all columns].
REQUIRED ARGUMENTS
tracks Can be one or more ASCII, native binary, or COARDS netCDF 1-D
data files. To supply the data files via a text file with a list
of tracks (one per record), specify the name of the track list
after a leading equal-sign (e.g., =tracks.lis). If the names are
missing their file extension we will append the suffix specified
for this TAG. Track files will be searched for first in the cur-
rent directory and second in all directories listed in
$X2SYS_HOME/TAG/TAG_paths.txt (if it exists). [If $X2SYS_HOME is
not set it will default to $GMT_SHAREDIR/x2sys]. (Note: MGD77
files will also be looked for via MGD77_HOME/mgd77_paths.txt and
*.gmt files will be searched for via $GMT_SHAREDIR/mgg/gmt-
file_paths).
-TTAG Specify the x2sys TAG which tracks the attributes of this data
type.
OPTIONAL ARGUMENTS
-A Eliminate COEs by distributing the COE between the two tracks in
proportion to track weight. These (dist, adjustment) spline
knots files for each track and data column are called track.col-
umn.adj and are expected to be in the $X2SYS_HOME/TAG directory.
The adjustments are only applied if the corresponding adjust
file can be found [No residual adjustments]
-E Enhance ASCII output by writing GMT segment headers between data
from each track [no segment headers].
-Fname1,name2,a|
Give a comma-separated sub-set list of column names defined in
the definition file. [Default selects all data columns].
-I[list]
Name of ASCII file with a list of track names (one per record)
that should be excluded from consideration [Default includes all
tracks].
-L[corrtable]
Apply optimal corrections to columns where such corrections are
available. Append the correction table to use [Default uses the
correction table TAG_corrections.txt which is expected to reside
in the $X2SYS_HOME/TAG directory]. For the format of this file,
see CORRECTIONS below.
-Rwest/east/south/north[/zmin/zmax][+r][+uunit]
west, east, south, and north specify the region of interest, and
you may specify them in decimal degrees or in
[A+-]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 for grid creation, give Rcodelon/lat/nx/ny, where
code is a 2-character combination of L, C, R (for left, center,
or right) and T, M, B for top, middle, or bottom. e.g., BL for
lower left. This indicates which point on a rectangular region
the lon/lat coordinate refers to, and the grid dimensions nx and
ny with grid spacings via -I is used to create the corresponding
region. Alternatively, specify the name of an existing grid
file and the -R settings (and grid spacing, if applicable) are
copied from the grid. Appending +uunit expects projected (Carte-
sian) coordinates compatible with chosen -J and we inversely
project to determine actual rectangular geographic region. For
perspective view (-p), optionally append /zmin/zmax. In case of
perspective view (-p), a z-range (zmin, zmax) can be appended to
indicate the third dimension. This needs to be done only when
using the -Jz option, not when using only the -p option. In the
latter case a perspective view of the plane is plotted, with no
third dimension. For Cartesian data just give
xmin/xmax/ymin/ymax. This option limits the COEs to those that
fall inside the specified domain.
-S Suppress output records where all the data columns are NaN
[Default will output all records].
-V[level] (more a|)
Select verbosity level [c].
-bo[ncols][type] (more a|)
Select native binary output.
-donodata (more a|)
Replace output columns that equal NaN with nodata.
-h[i|o][n][+c][+d][+rremark][+rtitle] (more a|)
Skip or produce header record(s).
-^ or just -
Print a short message about the syntax of the command, then
exits (NOTE: on Windows just use -).
-+ or just +
Print an extensive usage (help) message, including the explana-
tion of any module-specific option (but not the GMT common
options), then exits.
-? or no arguments
Print a complete usage (help) message, including the explanation
of all options, then exits.
EXAMPLES
To extract all data from the old-style MGG supplement file c2104.gmt,
recognized by the tag GMT:
gmt x2sys_datalist c2104.gmt -TGMT > myfile
To make lon,lat, and depth input for blockmean and surface using all
the files listed in the file tracks.lis and define by the tag TRK, but
only the data that are inside the specified area, and make output
binary, run
gmt x2sys_datalist =tracks.lis -TTRK -Fon,lat,depth -R40/-30/25/35 -bo > alltopo_bin.xyz
CORRECTIONS
The correction table is an ASCII file with coefficients and parameters
needed to carry out corrections. This table is usually produced by
x2sys_solve. Comment records beginning with # are allowed. All correc-
tion records are of the form
trackID observation correction
where trackID is the track name, observation is one of the abbrevia-
tions for an observed field contained in files under this TAG, and cor-
rection consists of one or more white-space-separated terms that will
be subtracted from the observation before output. Each term must have
this exact syntax:
factor[*[function]([scale](abbrev[-origin]))[^power]]
where terms in brackets are optional (the brackets themselves are not
used but regular parentheses must be used exactly as indicated). No
spaces are allowed except between terms. The factor is the amplitude of
the basis function, while the optional function can be one of sin, cos,
or exp. The optional scale and origin can be used to translate the
argument (before giving it to the optional function). The argument
abbrev is one of the abbreviations for columns known to this TAG. How-
ever, it can also be one of the three auxiliary terms dist (for
along-track distances), azim for along-track azimuths, and vel (for
along-track speed); these are all sensitive to the -C and -N settings
used when defining the TAB; furthermore, vel requires time to be
present in the data. If origin is given as T it means that we should
replace it with the value of abbrev for the very first record in the
file (this is usually only done for time). If the first data record
entry is NaN we revert origin to zero. Optionally, raise the entire
expression to the given power, before multiplying by factor. The fol-
lowing is an example of fictitious corrections to the track ABC, imply-
ing the z column should have a linear trend removed, the field obs
should be corrected by a strange dependency on latitude, weight needs
to have 1 added (hence correction is given as -1), and fuel should be
reduced by a linear distance term:
ABC z 7.1 1e-4*((time-T))
ABC obs 0.5*exp(-1e-3(lat))^1.5
ABC weight -1
ABC fuel 0.02*((dist))
SEE ALSO
blockmean(1), gmt(1), surface(1), x2sys_init(1), x2sys_datalist(1),
x2sys_get(1), x2sys_list(1), x2sys_put(1), x2sys_report(1),
x2sys_solve(1)
COPYRIGHT
2017, P. Wessel, W. H. F. Smith, R. Scharroo, J. Luis, and F. Wobbe
5.4.2 Jun 24, 2017 x2sys_datalist(1)
gmt5 5.4.2 - Generated Thu Jun 29 18:05:33 CDT 2017