x2sys_list
x2sys_list - Extract subset from crossover data base
Synopsis
x2sys_list -Ccolumn -TTAG [ coedbase.txt ]
[ -Aasymm_max ]
[ -E ]
[ -FacdhiInNtTvwxyz ]
[ -I[list] ]
[ -L[corrtable] ]
[ -Nnx_min ]
[ -Qe|i ]
[ -Rregion ]
[ -Strack ]
[ -V[level] ]
[ -W[list] ]
[ -bo<binary> ]
Note: No space is allowed between the option flag and the associated arguments.
Description
x2sys_list will read the crossover ASCII data base coedbase.txt
(or stdin) and extract a subset of the crossovers based on the other
arguments. The output may be ASCII or binary.
Required Arguments
- -Ccolumn
- Specify which data column you want to process. Crossovers related to
this column name must be present in the crossover data base.
- -TTAG
- Specify the x2sys TAG which tracks the attributes of this data type.
Optional Arguments
- coedbase.txt
- The name of the input ASCII crossover error data base as produced by
x2sys_cross. If not given we read standard input instead.
- -Aasymm_max
- Specifies maximum asymmetry in the distribution of crossovers
relative to the mid point in time (or distance, if not time is
available). Asymmetry is computed as (n_right - n_left)/(n_right
+ n_left), referring the the number of crossovers that falls in the
left or right half of the range. Symmetric distributions will have
values close to zero. If specified, we exclude tracks whose
asymmetry exceeds the specify cutoff in absolute value [1, i.e.,
include all].
- -E
- Enhance ASCII output by writing GMT segment headers with name of the
two tracks and their total number of cross-overs [no segment headers].
- -FacdhiInNtTvwxyz
- Specify your desired output using any combination of
acdhiInNtTvwxyz, in any order. Do not use space between the
letters, and note your selection is case-sensitive. The output will
be ASCII (or binary, -bo) columns of
values. Description of codes: a is the angle (< 90) defined by
the crossing tracks, c is crossover value of chosen observation
(see -C), d is distance along track, h is heading along
track, i is the signed time interval between the visit at the
crossover of the two tracks involved, I is same as i but is
unsigned, n is the names of the two tracks, N is the id
numbers of the two tracks, t is time along track in
dateTclock format (NaN if not available), T is
elapsed time since start of track along track (NaN if not
available), v is speed along track, w is the composite
weight, x is x-coordinate (or longitude), y is
y-coordinate (or latitude), and z is observed value (see
-C) along track. If -S is not specified then
d,h,n,N,t,T,v results in two
output columns each: first for track one and next for track two (in
lexical order of track names); otherwise, they refer to the
specified track only (except for n,N which then refers to
the other track). The sign convention for c,i is track one
minus track two (lexically sorted). Time intervals will be returned
according to the TIME_UNIT GMT defaults setting.
- -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 the chosen observable. 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
x2sys_solve.
- -Nnx_min
- Only report data from pairs that generated at least nx_min
crossovers between them [use all pairs].
- -Qe|i
- Append e for external crossovers or i for internal
crossovers only [Default is all crossovers].
- -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 bases the
statistics on those COE that fall inside the specified domain.
- -Strack
- Name of a single track. If given we restrict output to those
crossovers involving this track [Default output is crossovers
involving any track pair].
- -V[level] (more ...)
- Select verbosity level [c].
- -W[list]
- Name of ASCII file with a list of track names and their relative
weights (one track per record) that should be used to calculate the
composite crossover weight (output code w above). [Default sets
weights to 1].
- -bo[ncols][type] (more ...)
- Select native binary output.
- -^ 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 find all the magnetic crossovers associated with the tag MGD77 from
the file COE_data.txt, restricted to occupy a certain region in the
south Pacific, and return location, time, and crossover value, try
gmt x2sys_list COE_data.txt -V -TMGD77 -R180/240/-60/-30 -Cmag -Fxytz > mag_coe.txt
To find all the faa crossovers globally that involves track 12345678 and
output time since start of the year, using a binary double precision
format, try
gmt x2sys_list COE_data.txt -V -TMGD77 -Cfaa -S12345678 -FTz -bod > faa_coe.b