[gdal-dev] Setting the spatial reference of an existing shapefile with OGR

[Even Rouault]

Selon Jason Roberts <jason.roberts at duke.edu>:

> Greetings OGR experts,
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> I have a shapefile for which no spatial reference was defined when the
> shapefile was created, but I know the spatial reference and would like to
> set it on this existing shapefile. Is this possible with the OGR Python API?
>

You're correct. There's no direct (Python or C) API for this.

>
> It looks like the only place that takes an OGRSpatialReference instance is
> OGRDataSource::CreateLayer. This suggests that the only way to do it is to
> call CreateLayer with the appropriate OGRSpatialReference instance and then
> write all of the code to create the fields and copy all of the features from
> the existing layer to the new one. Is this correct?
>

Yes. Or... you could cheat a bit. In the case of a shapefile, the spatial
reference is written in a .prj file. So technically you can create a fake empty
shapefile with the right spatial reference, close it, rename the .prj to have
the same basename as your shapefile of interes and re-open it.

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> Thanks very much for any suggestions you can provide,
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> Jason
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