---
name: "x_list"
section: "1gmt"
platform: "linux"
package: "gmt"
version: "4.5.12-1"
release: "Debian 8 (Jessie)"
platforms: ["linux"]
url: "https://new.carta.tech/x_list"
---

# x\_list(1gmt)

Extract Cross-Over Information from the Data Base.

## NAME

**x\_list** - Extract Cross-Over Information from the Data Base.

## SYNOPSIS

**x\_list** \[ *leg1* \] \[ *leg2* \] \[ **-***dataflags* \]  \[ **-R***west/east/south/north* \]  \[ **-X***xbase* \] \[ **-H** \] \[ **-I** \]  \[ **-V** \] \[ **-C***corrfile* \] \[ **-Z***ignorefile* \]

## 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)](/GMT/1.md), *x\_system*(1)

## REFERENCES

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