x2sys_datalistgmt - Online in the Cloud

PROGRAM:

NAME

x2sys_datalist - Extract content of track data files

SYNOPSIS

x2sys_datalist track(s) -TTAG [ ] [ ] [ name1,name2,...) ] [ [list] ] [ [corrtable] ] [
region ] [ ] [ [ [level] ] [ -bo<binary> ] [ -do<nodata> ] [ -h<headers> ]

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 option. You may
limit the output to a geographic region, and insist that the output from several files be
separated 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 current 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/gmtfile_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.column.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,...)
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.

-R[unit]west/east/south/north[/zmin/zmax][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 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.
Using -Runit expects projected (Cartesian) 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 ...)
Select verbosity level [c].

-bo[ncols][type] (more ...)
Select native binary output.

-donodata (more ...)
Replace output columns that equal NaN with nodata.

-h[i|o][n][+c][+d][+rremark][+rtitle] (more ...)
Skip or produce header record(s).

-^ or just -
Print a short message about the syntax of the command, then exits (NOTE: on Windows
use just -).

-+ or just +
Print an extensive usage (help) message, including the explanation 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 options, then
exits.

--version
Print GMT version and exit.

--show-datadir
Print full path to GMT share directory and exit.

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 correction records are of the form

trackID observation correction

where trackID is the track name, observation is one of the abbreviations for an observed
field contained in files under this TAG, and correction 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. However, 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 following is an example of fictitious corrections to the
track ABC, implying 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))

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