X_LIST(1gmt)						       Generic Mapping Tools						      X_LIST(1gmt)

NAME

       x_list - Extract Cross-Over Information from the Data Base.

SYNOPSIS

       x_list [ leg1 ] [ leg2 ] [ -dataflags ] [ -Rwest/east/south/north ] [ -Xxbase ] [ -H ] [ -I ] [ -V ] [ -Ccorrfile ] [ -Zignorefile ]

DESCRIPTION

       x_list  will  allow  the  user to extract information from the xx_base.b and xx_legs.b files.  Several options can be passed on the command
       line in order to specify which parameters to extract. They are:

       leg1 leg2
	      If two legs are specified, the cross-overs they have in common are returned.  If one leg is specified, all the external  cross-overs
	      involving  this  leg  are  returned, OR only its internal cross-overs if -I is selected.	If no legs are given, all the external (or
	      internal with -I) cross-overs are returned.  This program is useful if one wants to look at, say, gravity COEs versus time from port
	      for a particular leg, etc.

       dataflags
	      This is a string of any combination of the following:
		   l means list both legnames.
		   t means list time.
		   x means list longitude.
		   y means list latitude.
		   g means list gravity COEs.
		   m means list magnetics COEs.
		   b means list bathymetry COEs.
		   G means list average gravity at cross-over.
		   M means list average magnetic anomaly at cross-over.
		   B means list average bathymetry at cross-over.
		   h means list heading of ship at cross-over.
	      The  components  are  written out in the order they appear in dataflags. The default output is -txygmbGMBhl.  When internal COEs are
	      desired, the time reported is the elapsed time since the ship first occupied the cross-over point. For external COEs the time  means
	      time from the start of the year in seconds.

       -R     Only return cross-overs inside the specified region west, east, south, and north.  [Default is world].

       -X     Indicate alternate xx_base.b file.

       -H     Issue one header record on output.

       -I     Report on internal COEs [Default is external COEs].

       -C     Apply  cross-over  correction to the data (i.e. reports the cross-over value after the best-fitting corrections have been applied to
	      both legs). If no corrfile is given, the default correction file is assumed.

       -Z     Ignore those legs that appear in the ignorefile.

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

SEE ALSO

       GMT(1), x_system(1)

REFERENCES

       Wessel, P. XOVER: A Cross-over Error Detector for Track Data, Computers & Geosciences, 15, 333-346.

GMT 4.5.7							    15 Jul 2011 						      X_LIST(1gmt)