Ubuntu Manpage: gpx - Extracts waypoints, tracks and routes from GPX files

NAME

       gpx - Extracts waypoints, tracks and routes from GPX files

SYNOPSIS

       package require Tcl  8.5

       package require gpx  ?0.9?

       ::gpx::Create gpxFilename ?rawXML?

       ::gpx::Cleanup token

       ::gpx::GetGPXMetadata token

       ::gpx::GetWaypointCount token

       ::gpx::GetAllWaypoints token

       ::gpx::GetTrackCount token

       ::gpx::GetTrackMetadata token whichTrack

       ::gpx::GetTrackPoints token whichTrack

       ::gpx::GetRouteCount token

       ::gpx::GetRouteMetadata token whichRoute

       ::gpx::GetRoutePoints token whichRoute

_________________________________________________________________________________________________

DESCRIPTION

       This  module  parses  and  extracts waypoints, tracks, routes and metadata from a GPX (GPS
       eXchange) file. Both GPX version 1.0 and 1.1 are supported.

COMMANDS

::gpx::Create gpxFilename ?rawXML?
The ::gpx::Create is the first command called to process GPX data. It takes the GPX
data from either the rawXML parameter if present or from the contents of
gpxFilename, and parses it using tdom. It returns a token value that is used by all
the other commands.

::gpx::Cleanup token
This procedure cleans up resources associated with token. It is strongly
recommended that you call this function after you are done with a given GPX file.
Not doing so will result in memory not being freed, and if your app calls
::gpx::Create enough times, the memory leak could cause a performance hit...or
worse.

::gpx::GetGPXMetadata token
This procedure returns a dictionary of the metadata associated with the GPX data
identified by token. The format of the metadata dictionary is described below, but
keys version and creator will always be present.

::gpx::GetWaypointCount token
This procedure returns the number of waypoints defined in the GPX data identified
by token.

::gpx::GetAllWaypoints token
This procedure returns the a list of waypoints defined in the GPX data identified
by token. The format of each waypoint item is described below.

::gpx::GetTrackCount token
This procedure returns the number of tracks defined in the GPX data identified by
token.

::gpx::GetTrackMetadata token whichTrack
This procedure returns a dictionary of the metadata associated track number
whichTrack (1 based) in the GPX data identified by token. The format of the
metadata dictionary is described below.

::gpx::GetTrackPoints token whichTrack
The procedure returns a list of track points comprising track number whichTrack (1
based) in the GPX data identified by token. The format of the metadata dictionary
is described below.

::gpx::GetRouteCount token
This procedure returns the number of routes defined in the GPX data identified by
token.

::gpx::GetRouteMetadata token whichRoute
This procedure returns a dictionary of the metadata associated route number
whichRoute (1 based) in the GPX data identified by token. The format of the
metadata dictionary is described below.

::gpx::GetRoutePoints token whichRoute
The procedure returns a list of route points comprising route number whichRoute (1
based) in the GPX data identified by token. The format of the metadata dictionary
is described below.

DATA STRUCTURES

       metadata dictionary
              The metadata associated with either the GPX document, a track, a route, a waypoint,
              a track point or route point  is  returned  in  a  dictionary.  The  keys  of  that
              dictionary  will  be whatever optional GPX elements are present. The value for each
              key depends on the GPX schema for that  element.  For  example,  the  value  for  a
              version  key  will  be a string, while for a link key will be a sub-dictionary with
              keys href and optionally text and type.

       point item
              Each item in a track or route list of points consists of a list of three  elements:
              latitude,  longitude  and  metadata  dictionary. Latitude and longitude are decimal
              numbers. The metadata dictionary format is described above. For points in a  track,
              typically there will always be ele (elevation) and time metadata keys.

EXAMPLE

              % set token [::gpx::Create myGpxFile.gpx]
              % set version [dict get [::gpx::GetGPXMetadata $token] version]
              % set trackCnt [::gpx::GetTrackCount $token]
              % set firstPoint [lindex [::gpx::GetTrackPoints $token 1] 0]
              % lassign $firstPoint lat lon ptMetadata
              % puts "first point in the first track is at $lat, $lon"
              % if {[dict exists $ptMetadata ele]} {
                   puts "at elevation [dict get $ptMetadata ele] meters"
                }
              % ::gpx::Cleanup $token

REFERENCES

       [1]    GPX: the GPS Exchange Format (http://www.topografix.com/gpx.asp)

       [2]    GPX 1.1 Schema Documentation (http://www.topografix.com/GPX/1/1/)

       [3]    GPX 1.0 Developer's Manual (http://www.topografix.com/gpx_manual.asp)

AUTHOR

       Keith Vetter

BUGS, IDEAS, FEEDBACK

       This  document,  and  the  package  it  describes, will undoubtedly contain bugs and other
       problems.   Please  report  such  in   the   category   gpx   of   the   Tcllib   Trackers
       [http://core.tcl.tk/tcllib/reportlist].  Please also report any ideas for enhancements you
       may have for either package and/or documentation.

       When proposing code changes, please provide unified diffs, i.e the output of diff -u.

       Note further that attachments are strongly preferred over inlined patches. Attachments can
       be  made  by going to the Edit form of the ticket immediately after its creation, and then
       using the left-most button in the secondary navigation bar.

KEYWORDS

       gps, gpx

COPYRIGHT

       Copyright (c) 2010, Keith Vetter <kvetter@gmail.com>