NAME¶
x2sys_list - Output a subset of crossovers from data base
SYNOPSIS¶
x2sys_list -Ccolumn -TTAG [
coedbase.txt ] [
-Aasymm_max ] [
-FacdhiInNtTvwxyz ] [
-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] ]
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.
- -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 produced 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
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, 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 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
- 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 specified 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, heading (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 character 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 precision format, try
x2sys_list COE_data.txt
-V -T MGD77
-C faa
-S
12345678
-F Tz
-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)