Provided by: gmt_4.5.11-1build1_amd64 bug


       x2sys_list - Output a subset of crossovers from data base


       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] ]


       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.


       No space between the option flag and the associated arguments.

              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

       -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

       -R     west,  east,  south,  and north specify the Region of interest, and you may specify
              them in decimal degrees or in  [+-]dd:mm[][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

       -V     Selects verbose mode, which will send progress  reports  to  stderr  [Default  runs

       -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 '>'].


       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


       x2sys_binlist(1),   x2sys_cross(1),   x2sys_datalist(1),   x2sys_get(1),    x2sys_init(1),
       x2sys_put(1), x2sys_report(1), x2sys_solve(1)