[GRASS-stats] Mapset and layer names in readVECT using GRASS GDAL plugin
Rainer M Krug
Rainer at krugs.de
Thu Jun 18 09:33:25 PDT 2015
Roger Bivand <Roger.Bivand at nhh.no> writes:
> Hi,
>
> Thanks for your interest. I do not use the plugins at all, as they
> have historically led to great difficulty in managing and maintaining
> rgdal (I sometimes rebuild GDAL more than once a day). If you would
> like commit rights on R-Forge, please file a request there, and we can
> try to find ways of automating checking (or testing) the
> functionality, but without my contribution.
My fault - I forgot the mapset.
I just uploaded a fix - Thanks Ahmadou - exactly as you suggested.
Cheers,
Rainer
>
> Best wishes,
>
> Roger
>
> On Thu, 18 Jun 2015, Ahmadou Dicko wrote:
>
>> Hi,
>>
>> I'm trying to use the direct OGR access to GRASS vector using plugin
>> through the rgrass7 package in R but I have some issues with the
>> mapset argument.
>>
>> Here are the steps to reproduce the bug using the nc_basic_spm_grass7
>> GRASS location and user1 mapset.
>>
>> Within the GRASS session, we launch R
>> library(rgrass7)
>> v <- readVECT("geonames", plugin = TRUE)
>> Error in .read_vect_plugin(vname = vname, layer = layer, type = type, :
>> object 'mapset' not found
>>
>> One way to fix this, is to add a mapset argument to .read_vect_plugin
>> and set it by default to the same argument in the readVECT function.
>>
>> ### Example of fix
>> readVECT <- function(..., mapset = NULL, ...) {
>> ....
>> if (plugin) {
>> res <- .read_vect_plugin(..., mapset = mapset, ...)
>> ....
>> }
>>
>> But once this problem solved, another one appears. This one, need
>> confirmation though. Using the GRASS GDAL plugin, I can't open a GRASS
>> vector without using the layer name. I am aware that we can use the
>> layer number using other driver (Shapefiles, GML, etc) but I looks
>> like (at least in my setup) that I can't open it without giving the
>> layer name.
>>
>> I modified rgrass7:::.read_vect_plugin and named it .read_vect_plugin2
>> and added a mapset argument (to correct the first bug).
>>
>> ### Reproducing the error
>> sss <- strsplit(packageDescription("rgdal")$Version, "-")[[1]]
>>
>> class(
>> .read_vect_plugin2("geonames",
>> mapset = NULL,
>> layer = 1L,
>> sss = sss,
>> ignore.stderr = TRUE,
>> pointDropZ = TRUE)
>> )
>> Error in ogrInfo(dsn = dsn, layer = layer, encoding = encoding,
>> use_iconv = use_iconv, :
>> Cannot open layer
>>
>>
>> class(
>> .read_vect_plugin2("geonames",
>> mapset = NULL,
>> layer = "geonames",
>> sss = sss,
>> ignore.stderr = TRUE,
>> pointDropZ = TRUE)
>> )
>> [1] "SpatialPointsDataFrame"
>> attr(,"package")
>> [1] "sp"
>>
>> Please can you confirm that it is a feature of the plugin to have the
>> real name instead of the layer number ?
>>
>> Nonetheless, one way to fix this is to add a call to
>> rgdal::ogrListLayers in the rgrass7:::.read_vect_plugin
>>
>> dsn <- paste(gg$GISDBASE, gg$LOCATION_NAME, mapset, "vector",
>> vname[1], "head", sep = "/")
>> layers <- rgdal::ogrListLayers(dsn = dsn)
>>
>> Using this approach we can have the layer names and use it in readOGR.
>> I hope that I described it clearly.
>>
>> Best regards,
>>
>> Info and spec
>> Linux:
>> Linux dickoa 4.0.5-1-ARCH #1 SMP PREEMPT Sat Jun 6 18:37:49 CEST 2015
>> x86_64 GNU/Linux
>>
>> GRASS:
>> version=7.1.svn
>> date=2015
>> revision=65487
>> build_date=2015-06-16
>> build_platform=x86_64-unknown-linux-gnu
>>
>> GDAL:
>> GDAL 1.11.2, released 2015/02/10
>>
>>
>> R:
>> sessionInfo()
>> R version 3.2.1 RC (2015-06-14 r68519)
>> Platform: x86_64-unknown-linux-gnu (64-bit)
>> Running under: Arch Linux
>>
>> locale:
>> [1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C
>> [3] LC_TIME=en_US.UTF-8 LC_COLLATE=en_US.UTF-8
>> [5] LC_MONETARY=en_US.UTF-8 LC_MESSAGES=en_US.UTF-8
>> [7] LC_PAPER=en_US.UTF-8 LC_NAME=C
>> [9] LC_ADDRESS=C LC_TELEPHONE=C
>> [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
>>
>> attached base packages:
>> [1] stats graphics grDevices utils datasets methods
>> [7] base
>>
>> other attached packages:
>> [1] rgdal_0.9-3 rgrass7_0.1-0 XML_3.98-1.2 sp_1.1-1
>>
>> loaded via a namespace (and not attached):
>> [1] tools_3.2.1 grid_3.2.1 lattice_0.20-31
>>
>>
>>
>> --
>> Ahmadou H. DICKO
>> statistician economist (Ingénieur Statisticien Économiste)
>> PhD candidate in Climate change economics
>> Faculty of economics and managment - Cheikh Anta Diop University
>> West African Science Service Center on Climate Change and Adaptated
>> Land Use (WASCAL)
>> Center for Development Research (ZEF) - University of Bonn
>> email : ahmadou.dicko at ucad.edu.sn
>> twitter : @dickoah
>> github : github/dickoa
>> tel : +221 33 827 55 16
>> portable: +221 77 123 81 69
>> _______________________________________________
>> grass-stats mailing list
>> grass-stats at lists.osgeo.org
>> http://lists.osgeo.org/mailman/listinfo/grass-stats
--
Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation Biology, UCT), Dipl. Phys. (Germany)
Centre of Excellence for Invasion Biology
Stellenbosch University
South Africa
Tel : +33 - (0)9 53 10 27 44
Cell: +33 - (0)6 85 62 59 98
Fax : +33 - (0)9 58 10 27 44
Fax (D): +49 - (0)3 21 21 25 22 44
email: Rainer at krugs.de
Skype: RMkrug
PGP: 0x0F52F982
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 480 bytes
Desc: not available
URL: <http://lists.osgeo.org/pipermail/grass-stats/attachments/20150618/0f2fa709/attachment.pgp>
More information about the grass-stats
mailing list