[R-sig-Geo] Wrong reading of data type in readOGR ?

[Roger Bivand]

On Fri, 25 Nov 2016, Patrick Giraudoux wrote:

> Dear Listers,
>
> I meet a problem with readOGR on an ESRI shapefile which was correctly read 
> in the past (practical training with students). Now all integer variables are 
> read as "factors" although they should be read as integer. With the argument 
> stringsAsFactors=FALSE, the reading gives "characters", but not the expected 
> integers.

Please see:

https://stat.ethz.ch/pipermail/r-sig-geo/2016-October/025038.html

https://stat.ethz.ch/pipermail/r-sig-geo/2016-November/025104.html

This is the result of the antiquated way DBF handle numbers, and changes 
made in GDAL2 to accommodate 64-bit integers, which most often are IDs, 
not numbers. Maybe try the GDAL1_integer64_policy= argument, or re-write 
the shapefiles with the offending integer written as a double, or stop 
using shapefiles.

Roger

>
> Reading the corresponding *.dbf file with foreign:read.dbf gives a correct 
> reading. This makes me suspect that something goes wrong with the last 
> version of readOGR (maybe earlier too). Those installed one year ago in the 
> computer room are OK.
>
> Any suggestion/idea?
>
> Best,
>
> Patrick
>
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-- 
Roger Bivand
Department of Economics, Norwegian School of Economics,
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