x2sys_list(1) GMT x2sys_list(1)
NAME
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] ] [
-bobinary ]
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 argu-
ments. 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 pro-
duced 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 acdhiIn-
NtTvwxyz, 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 avail-
able), 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 spec-
ified 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].
-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 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 a|)
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 a|)
Select native binary output.
-^ 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 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 preci-
sion format, try
gmt x2sys_list COE_data.txt -V -TMGD77 -Cfaa -S12345678 -FTz -bod > faa_coe.b
SEE ALSO
x2sys_binlist(1), x2sys_cross(1), x2sys_datalist(1), x2sys_get(1),
x2sys_init(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_list(1)
gmt5 5.4.2 - Generated Thu Jun 29 18:22:07 CDT 2017