[Gpsbabel-misc] Zero altitude causes problem with KML output

[Isaac W. <is...@wi...>]

While trying to write a shell script to delete one of each pair of duplicated coordinates in a KML file (a problem I mentioned in a previous message), I discovered another problem. When the altitude entry in a gpx file is zero:

<?xml version='1.0' encoding='UTF-8'?>
<gpx version='1.1' creator='GPSMID' xmlns='http://www.topografix.com/GPX/1/1'>
<trk>
<trkseg>
<trkpt lat='37.26142' lon='-121.89242'>
<ele>38</ele>
<time>2011-08-24T21:13:33Z</time>
</trkpt>
<trkpt lat='37.261414' lon='-121.89239'>
<ele>0</ele>
<time>2011-08-24T21:13:45Z</time>
</trkpt>
<trkpt lat='37.26142' lon='-121.89241'>
<ele>0</ele>
<time>2011-08-24T21:13:51Z</time>
</trkpt>
<trkpt lat='37.261475' lon='-121.89246'>
<ele>0</ele>
<time>2011-08-24T21:13:59Z</time>
</trkpt>
...

Then the corresponding entries in the resulting KML file are entirely omitted:

<Placemark>
<name>Path</name>
<styleUrl>#lineStyle</styleUrl>
<LineString>
<tessellate>1</tessellate>
<coordinates>
-121.892420,37.261420,38.00
-121.892420,37.261420,38.000000
-121.892390,37.261414
-121.892390,37.261414
-121.892410,37.261420
-121.892410,37.261420
-121.892460,37.261475
-121.892460,37.261475
-121.892430,37.261510
-121.892430,37.261510
-121.892420,37.261530,59.00
-121.892420,37.261530,59.000000
-121.892420,37.261536
-121.892420,37.261536
-121.892370,37.261547,56.00
-121.892370,37.261547,56.000000
...

This not only frustrated my intention of deleting all lines containing ".000000" as a way of eliminating the duplicates, but also is probably not good practice for data which may be used in a structured database.

Zero values for latitude and longitude seem to be handled properly.

Isaac