X2SYS_LIST(1) Generic Mapping Tools X2SYS_LIST(1)NAMEx2sys_list - Output a subset of crossovers from data base
SYNOPSISx2sys_list-Ccolumn -TTAG [ coedbase.txt ] [ -Aasymm_max ] [ -FacdhiIn‐
NtTvwxyz ] [ -I[list] ] [ -L[corrtable] ] [ -Nnx_min ] [ -Qe|i ] [
-Rwest/east/south/north[r] ] [ -S[+]track ] [ -V ] [ -W[list] ] [
-bo[s|S|d|D[ncol]|c[var1/...]] ] [ -m[flag] ]
DESCRIPTIONx2sys_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.
-C Specify which data column you want to process. Crossovers
related to this column name must be present in the crossover
data base.
-T Specify the x2sys TAG which tracks the attributes of this data
type.
OPTIONS
No space between the option flag and the associated 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.
-A Specifies maximum asymmetry in the distribution of crossovers
relative to the mid point in time (or distance, if time is not
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].
-F 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, see -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
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 Name of ASCII file with a list of track names (one per record)
that should be excluded from consideration [Default includes all
tracks].
-L 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.
-N Only report data from pairs that generated at least nx_min
crossovers between them [use all pairs].
-Q Append e for external crossovers or i for internal crossovers
only [Default is all crossovers].
-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. For Cartesian data just give xmin/xmax/ymin/ymax.
This option limits the COEs to those that fall inside the speci‐
fied domain.
-S Name of a single track. If given we restrict output to those
crossovers involving this track [Default output is crossovers
involving any track pair]. Prepend a '+' to make it print info
relative to both tracks [Default is selected track]. This
applies only to common information such as distance, time, head‐
ing (see -F for details).
-V Selects verbose mode, which will send progress reports to stderr
[Default runs "silently"].
-W 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 Selects binary output. Append s for single precision [Default
is d (double)]. Uppercase S or D will force byte-swapping.
Optionally, append ncol, the number of desired columns in your
binary output file.
-m Multiple segment output format. Segments with crossovers for a
single track pair are separated by a record whose first charac‐
ter is flag and contains the two track names. [Default is '>'].
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
x2sys_list COE_data.txt -V -T MGD77 -R 180/240/-60/-30 -C mag -F xytz >
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
x2sys_list COE_data.txt -V -T MGD77 -C faa -S 12345678 -F Tz -bod >
faa_coe.b
SEE ALSOx2sys_binlist(1), x2sys_cross(1), x2sys_datalist(1), x2sys_get(1),
x2sys_init(1), x2sys_put(1), x2sys_report(1), x2sys_solve(1)GMT 4.5.14 1 Nov 2015 X2SYS_LIST(1)
