[gdal-dev] converting csv to kml: locations displaced in
GoogleEarth
Dane Springmeyer
blake at hailmail.net
Thu Jan 10 17:55:29 EST 2008
Even and Chris -
Great, thanks for the clarification! That makes perfect sense now
that I understand the idea behind a VRT file.
I think the current non-trac documentation is great but would benefit
from spelling out that the VRT datasource is made by hand - just like
Even mentioned.
For new users it might be helpful to have these steps in a tutorial
somewhere. I could write that up quickly - where might be the best
place to put it? Maybe a "How do I convert CSV to KML?" in this
spot: http://trac.osgeo.org/gdal/wiki/FAQVector
Is there a spot on trac for driver specific info that I could help
out with adding info to as well?
Thanks,
Dane
On Jan 10, 2008, at 2:38 PM, Christopher Condit wrote:
> Just to clear this up if it isn't already: if the CSV file in
> question is called "test.csv" and I create a separate VRT file
> called "test.vrt" (in the same directory as "test.csv") with the
> following content:
> <OGRVRTDataSource>
> <OGRVRTLayer name="test">
> <SrcDataSource>test.csv</SrcDataSource>
> <GeometryType>wkbPoint</GeometryType>
> <LayerSRS>WGS84</LayerSRS>
> <GeometryField encoding="PointFromColumns" x="Longitude"
> y="Latitude"/>
> </OGRVRTLayer>
> </OGRVRTDataSource>
>
> I can then treat the test.vrt file as a read-only OGR data source.
> And when I run the transform:
> ogr2ogr -f KML test.kml test.vrt
> I end up with:
> <?xml version="1.0" encoding="utf-8" ?>
> <kml xmlns="http://earth.google.com/kml/2.0">
> <Document><Folder><name>test</name>
> <Placemark>
> <name>First point</name>
> <description>
> <![CDATA[
> <b>Latitude:</b> <i>48.1</i><br />
> <b>Longitude:</b> <i>0.25</i><br />
> ]]></description>
> <Point><coordinates>0.25,48.1,0</coordinates></Point>
> </Placemark>
> <Placemark>
> <name>Second point</name>
> <description>
> <![CDATA[
> <b>Latitude:</b> <i>49.2</i><br />
> <b>Longitude:</b> <i>1.1</i><br />
> ]]></description>
> <Point><coordinates>1.1,49.200000000000003,0</coordinates></
> Point>
> </Placemark>
> <Placemark>
> <name>Third point</name>
> <description>
> <![CDATA[
> <b>Latitude:</b> <i>47.5</i><br />
> <b>Longitude:</b> <i>0.75</i><br />
> ]]></description>
> <Point><coordinates>0.75,47.5,0</coordinates></Point>
> </Placemark>
> </Folder></Document></kml>
>
> Even - I think the documentation is straightforward...
>
> -Chris
>
>
> -----Original Message-----
> From: gdal-dev-bounces at lists.osgeo.org [mailto:gdal-dev-
> bounces at lists.osgeo.org] On Behalf Of Even Rouault
> Sent: Thursday, January 10, 2008 14:32
> To: Dane Springmeyer
> Cc: gdal-dev at lists.osgeo.org
> Subject: Re: [gdal-dev] converting csv to kml: locations displaced
> in GoogleEarth
>
> Dane,
>
> I'm the one who wrote that part of the CSV doc indeed...
> Sorry that it's not clearer. What I meant by "You can write the
> associated VRT
> file (test.vrt)" is indeed "You must create at hand an associated
> VRT file
> (test.vrt)". You create it at hand, and then gives it as an input
> to OGR, so
> it can understand the structure of the underlying CSV file. I hope
> it makes
> things clearer...
> If people have suggestions to formulate it more clearly in the
> docs, let me
> know.
>
> Best regards
>
> Le Thursday 10 January 2008 23:09:01, vous avez écrit :
>> Hi Even,
>>
>> the csv to vrt docs here: http://www.gdal.org/ogr/drv_csv.html
>>
>> say to "write" a vrt but from the format's list and the error message
>> I get it seems VRT is still read-only in Gdal 1.5
>>
>> Am I missing something?
>>
>> I get:
>> ____
>>
>> [tropicana]$ ogr2ogr -f VRT test.vrt test.csv
>> VRT driver does not support data source creation.
>> ____
>>
>> - dane
>>
>> On Jan 10, 2008, at 1:19 PM, Even Rouault wrote:
>>> Answers below :
>>>
>>> Le Thursday 10 January 2008 21:54:09 Tim Michelsen, vous avez
>>> écrit :
>>>> Hello,
>>>> I would like to convert a csv file to kml. When I load the
>>>> resulting KML
>>>> into Googleearth (GE) the generated placemarks inside the file are
>>>> totally displaced.
>>>> What could be the reason?
>>>> Could it be that XML decription is used too old?
>>>>
>>>> When I export my places from GE I read this line:
>>>> <kml xmlns="http://earth.google.com/kml/2.1">
>>>>
>>>> In the generated KML file I can read:
>>>> <kml xmlns="http://earth.google.com/kml/2.0">
>>>
>>> OGR KML driver exports KML 2.0 for the moment, but that shouldn't
>>> be a
>>> problem.
>>>
>>>> Here are the test files:
>>>> Latitude,Longitude,Name
>>>> 48.1,0.25,"First point"
>>>> 49.2,1.1,"Second point"
>>>> 47.5,0.75,"Third point"
>>>>
>>>> the command line I used:
>>>> ogr2ogr -f "KML" test.kml test.csv
>>>>
>>>> the KML:
>>>> <?xml version="1.0" encoding="utf-8" ?>
>>>> <kml xmlns="http://earth.google.com/kml/2.0">
>>>> <Document><Folder><name>test</name>
>>>> <Placemark>
>>>> <description><![CDATA[
>>>> <b>Latitude:</b> <i>48.1</i><br />
>>>> <b>Longitude:</b> <i>0.25</i><br />
>>>> <b>Name:</b> <i>First point</i><br />
>>>> ]]></description> </Placemark>
>>>> <Placemark>
>>>> <description><![CDATA[
>>>> <b>Latitude:</b> <i>49.2</i><br />
>>>> <b>Longitude:</b> <i>1.1</i><br />
>>>> <b>Name:</b> <i>Second point</i><br />
>>>> ]]></description> </Placemark>
>>>> <Placemark>
>>>> <description><![CDATA[
>>>> <b>Latitude:</b> <i>47.5</i><br />
>>>> <b>Longitude:</b> <i>0.75</i><br />
>>>> <b>Name:</b> <i>Third point</i><br />
>>>> ]]></description> </Placemark>
>>>> </Folder></Document></kml>
>>>
>>> The generated KML file is obviously not what you would expect (it
>>> has output
>>> all the CSV fields into the description tag, and GE by default put
>>> such
>>> placemark at (0°,0°), which is at the west of Africa) . But that
>>> can be
>>> logically explained. You can't use a CSV file as simply as you do.
>>> If you
>>> read more carefully http://www.gdal.org/ogr/drv_csv.html, you'll
>>> see that you
>>> need to create a VRT file, test.vrt, and do ogr2ogr on that file,
>>> not on the
>>> original CSV file.
>>>
>>>> Attached you find the screenshot from GE.
>>>>
>>>> I would highly appreciate your hints and help.
>>>>
>>>> Kind regards,
>>>> Timmie
>>>>
>>>> P.S. The Mailserver would let my inital mail through. This one
>>>> comes
>>>> with a smaller image.
>>>
>>> _______________________________________________
>>> gdal-dev mailing list
>>> gdal-dev at lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>
>
> _______________________________________________
> gdal-dev mailing list
> gdal-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/gdal-dev
More information about the gdal-dev
mailing list