X_UPDATE(1gmt)						       Generic Mapping Tools						    X_UPDATE(1gmt)

NAME

       x_update - Archiving of Cross-Over Information

SYNOPSIS

       x_update cross-overfile [ -Xxbase ] [ -Llegbase ] [ -V ] [ -Wmax ]

DESCRIPTION

       x_update  reads	the  ASCII  file produced by x_over and writes the information to the database files xx_base.b and xx_legs.b (unless other
       filenames are specified on the command line) using a compact, binary format. The options recognized are:

       -X     Indicate alternate xx_base.b file.

       -L     Indicate alternate xx_legs.b file.

       -V     Selects verbose mode, which will send progress reports to stderr [Default runs "silently"].  Reports the pair currently  being  pro-
	      cessed.

       -W     Prints a warning if the number of COEs generated by any pair of legs exceed max.

BEWARE

       For security reasons the xx_legs.b are first renamed to xx_legs.b_old, to prevent loss of information if a black-out or system crash should
       occur during writing of the new xx_legs.b file. It is recommended that the old file is left on the disk in case of  other  disasters.  Note
       that x_update does not check if a pair of legs already exist in the xx_base.b file. It is the user's responsibility to ensure that duplica-
       tion of information does not occur. Should some pairs already in the database need to be re-examined, then run x_remove which will wipe out
       all  traces  of	the  specified	cruises  from  the  x_system  data  base  files.  Now we can pass the pairs that need to be redone through
       x_over/x_update again.

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_UPDATE(1gmt)