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

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NAME

       gpx - Extracts waypoints, tracks and routes from GPX files

SYNOPSIS

       package require Tcl 8.5 9

       package require gpx ?1.1?

       ::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>