[gdal-dev] save raster as point-vector file

[Mateusz Kędzior]

Hi Chaitanya,

I say that I don't need to create VRT file, but I was wrong. When I try to
run ogr2ogr utility:
*
ogr2ogr -f GML output_file.gml input_file.csv*

I discover that created file contain only table - if I choose ESRI shapefile
as output, I get only dbf file.

So i try to generate such file:

================================================================================
<OGRVRTDataSource>
    <OGRVRTLayer name="evap_OBC_OBCXYZn">
        <SrcDataSource>evap_OBC_OBCXYZn.csv</SrcDataSource>
        <GeometryType>wkbPoint</GeometryType>
        <LayerSRS>WGS84</LayerSRS>
        <GeometryField encoding="PointFromColumns" x="Longitude"
y="Latitude"/>
    </OGRVRTLayer>
</OGRVRTDataSource>
=================================================================================

but:

   - if I type .vrt file as input I get an empty GML file
   - if I I type .csv file as input I get an output which contain only table
   (without geometry)

How I can run it properly?
Which values are allowed in <GeometryField encoding> property?
===================
Best regards,
Mateusz

W dniu 10 sierpnia 2011 05:58 użytkownik Chaitanya kumar CH <
chaitanya.ch at gmail.com> napisał:

> Mateusz,
>
> You have to change the OGRVRTLayer name property to point to the file name
> without the extension.  Also change the SrcDataSource element.
>
> FYI, this process creates a vector file with points. gdal_polygonize
> produces polygons.
>
>
> 2011/8/10 Mateusz Kędzior <matandked at gmail.com>
>
>> Hi again,
>>
>> is it mandatory to create such file?
>> Regarding to information on GDAL/OGR page should I create simple text file
>> which contains only other OGRVRTLayer name property :
>>
>> <OGRVRTDataSource>
>>     <OGRVRTLayer name="test">
>>         <SrcDataSource>test.csv</SrcDataSource>
>>         <GeometryType>wkbPoint</GeometryType>
>>         <LayerSRS>WGS84</LayerSRS>
>>         <GeometryField encoding="PointFromColumns" x="Longitude" y="Latitude"/>
>>     </OGRVRTLayer>
>> </OGRVRTDataSource>
>>
>> ==============
>> Best regards,
>> Mateusz
>>
>> W dniu 9 sierpnia 2011 20:13 użytkownik Chaitanya kumar CH <
>> chaitanya.ch at gmail.com> napisał:
>>
>>> Create a text file with just the header. Use the cat command to join this
>>> file and the xyz file.
>>> $ cat HeaderFile.csv file1.csv > file1.cHi sv
>>>
>>> You can repeat this on all files in a shell script.
>>>
>>> Otherwise add the following line in the gdal2xyz.py script at line 144
>>> [1].
>>>
>>> dst_fh.write( 'Longitude,Latitude,Name' )
>>>
>>> You will also have to create a separate vrt file for each csv file. The
>>> SrcDataSource element value changes for each file.
>>>
>>> [1]:
>>> http://trac.osgeo.org/gdal/browser/trunk/gdal/swig/python/scripts/gdal2xyz.py?rev=21127#L145
>>>
>>>
>>> 2011/8/9 Mateusz Kędzior <matandked at gmail.com>
>>>
>>>> Chaitanya,
>>>>
>>>> if I understand properly, I need to add one line to each of processed
>>>> files.
>>>> How I can do it quickly? Is there any option in gdal2xyz.py script?
>>>>
>>>> If no - what would You recommend?
>>>> I think about sed utility, but it's general difficult in use.
>>>>
>>>> When I am thinking about Python I see only one possibility - load each
>>>> file to variable and then assign to another first line plus variable and at
>>>> last - save it.
>>>>
>>>> ==============
>>>> Best Regards,
>>>> Mateusz
>>>>
>>>> W dniu 9 sierpnia 2011 13:38 użytkownik Chaitanya kumar CH <
>>>> chaitanya.ch at gmail.com> napisał:
>>>>
>>>> Mateusz,
>>>>>
>>>>> gdal2xyz.py creates space delimited fields. Consider running it with
>>>>> the -csv option to delimit it with comma.
>>>>> Now you can almost use it as a csv format vector file. You just need to
>>>>> add a header row and define a small VRT file as described in OGR's CSV
>>>>> driver page[1].
>>>>> Run ogrinfo and ogr2ogr on the .vrt file to check the file.
>>>>>
>>>>> [1]: http://www.gdal.org/ogr/drv_csv.html
>>>>>
>>>>> 2011/8/9 Mateusz Kędzior <matandked at gmail.com>
>>>>>
>>>>>> Hello,
>>>>>>
>>>>>> I would like to show value of each raster cell as label. My idea (I
>>>>>> don't know any plugin or any functionality in GDAL/OGR which allow to do it
>>>>>> easier) is to export raster using gdal2xyz.py into coordinates-value format
>>>>>> and then save it as vector (GML or shapefile). For this second task, I try
>>>>>> to use
>>>>>>
>>>>>> =================================================================================================================================================
>>>>>> gdal_polygonize.py:
>>>>>> gdal_polygonize.py rainfXYZ.txt rainf.shp Creating output rainf.shp of
>>>>>> format GML. 0...10...20...30...40...50...60...70...80...90...100 - done.
>>>>>>
>>>>>> =================================================================================================================================================
>>>>>> unfortunately I am unable to load created file (even if I change the
>>>>>> extension to .gml)
>>>>>> ogr2ogr tool don't even recognize this format.
>>>>>>
>>>>>> =========================
>>>>>> Thank You in advance,
>>>>>> Mateusz
>>>>>>
>>>>>> _______________________________________________
>>>>>> gdal-dev mailing list
>>>>>> gdal-dev at lists.osgeo.org
>>>>>> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Best regards,
>>>>> Chaitanya kumar CH.
>>>>>
>>>>> +91-9494447584
>>>>> 17.2416N 80.1426E
>>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> Best regards,
>>> Chaitanya kumar CH.
>>>
>>> +91-9494447584
>>> 17.2416N 80.1426E
>>>
>>
>>
>
>
> --
> Best regards,
> Chaitanya kumar CH.
>
> +91-9494447584
> 17.2416N 80.1426E
>
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