NAME¶
x2sys_list - Output a subset of crossovers from data base
SYNOPSIS¶
x2sys_list -Ccolumn -TTAG [
coedbase.txt ] [
-Aasymm_max ] [
-FacdhiInNtTvxyz ] [
-I[
list] ] [
-L[
corrtable] ] [
-Nnx_min ] [
-Qe|
i
] [
-Rwest/
east/
south/
north[
r] ] [
-Strack ] [
-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 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].
- -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 comon
information such as distance, time, heading.
- -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 -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
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)