[R-sig-Geo] CSV with Geometry Column to SF object

argunaw . @rgun@w @end|ng |rom gm@||@com
Wed Oct 16 16:42:37 CEST 2019 

This is exactly what I was looking for and answers my question. Thank you
so much!

On Wed, Oct 16, 2019 at 4:41 AM Barry Rowlingson <b.rowlingson using gmail.com>
wrote:

> After a night's sleep, here's a full solution for your sample data frame:
>
> 1. convert the geometry strings to sf spatial objects:
> newGeom = st_as_sfc(structure(as.character(df$geom), class =
> "WKB"),EWKB=TRUE)
>
> 2. create a new spatial data frame with the new spatial objects as geometry
> sdf = st_set_geometry(df, newGeom)
>
> 3. (optional) drop the character format column
> sdf$geom=NULL
>
> Now you've got a standard `sf` spatial data frame with the converted
> geometry. If any of that is wrong I'm sure the real experts here will
> correct me.
>
> Barry
>
>
>
> On Tue, Oct 15, 2019 at 8:47 PM Barry Rowlingson <b.rowlingson using gmail.com>
> wrote:
>
>> These strings are hexadecimal WKB geometries. You should be able to turn
>> them back into geometries:
>>
>>  > s =
>> "0105000020D708000001000000010200000003000000009875DF60AC2D4100606296BDAC07410037DB98F1AC2D41001C5EFC79AA074180A23112E1AA2D41001E0E5F18A20741"
>>
>> by constructing a WKB object:
>>
>> > wkb = structure(list(s), class = "WKB")
>>
>> and then:
>>
>>  > st_as_sfc(wkb)
>> wkbType: 536870917
>> Error in CPL_read_wkb(x, EWKB, spatialite) :
>>   unsupported wkbType dim in switch
>>
>> but that error looks bad...
>>
>> ahaha, they are EWKB:
>>
>> > st_as_sfc(wkb, EWKB=TRUE)
>> Geometry set for 1 feature
>> geometry type:  MULTILINESTRING
>> dimension:      XY
>> bbox:           xmin: 972144.5 ymin: 193603 xmax: 972408.8 ymax: 193943.7
>> epsg (SRID):    2263
>> proj4string:    +proj=lcc +lat_1=41.03333333333333
>> +lat_2=40.66666666666666 +lat_0=40.16666666666666 +lon_0=-74
>> +x_0=300000.0000000001 +y_0=0 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0
>> +units=us-ft +no_defs
>> MULTILINESTRING ((972336.4 193943.7, 972408.8 1...
>>
>>
>> On Tue, Oct 15, 2019 at 8:40 PM argunaw . <argunaw using gmail.com> wrote:
>>
>>> Here is a small sample of the dataset I'm working with- the strings are
>>> really long for geometry, so apologies for the messiness.
>>>
>>> df = data.frame(a=1:5,
>>>
>>> geom=c("0105000020D70800000100000001020000000C000000003BA049F49B2E4100667C2F07460F410012BC05F09B2E4100303670E4480F410019849E1D9C2E41007A13FB1B4C0F4180AFF579479C2E41005C30996E4E0F41001E3A23509C2E4100D0F0A76A500F41803BD015919C2E41004A1AFBA7540F4180024687D89C2E4100BA8183FD560F418067F48E3D9D2E410064EAE9D4590F4100852B29879D2E41007AD06D445C0F410053C7ADB99D2E4100D614CECE5F0F41006A378D0F9E2E4100E6D2D363620F4180781D0D679E2E41007829482A660F41",
>>>
>>>
>>> "0105000020D70800000100000001020000000200000080048144E38A2E41001E996E65F20A41805C14EE428B2E41005617618EF50A41",
>>>
>>>
>>> "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",
>>>
>>>
>>> "0105000020D708000001000000010200000003000000009875DF60AC2D4100606296BDAC07410037DB98F1AC2D41001C5EFC79AA074180A23112E1AA2D41001E0E5F18A20741",
>>>
>>>
>>> "0105000020D708000001000000010200000004000000809F59A9A8E02D41009EACC82A130841807FA2D79DE02D410092AB7B64130841007843FF9CE02D41003434DFAE130841805FF302D9E02D41002AC2FE9C180841"))
>>>
>>> On Tue, Oct 15, 2019 at 3:30 PM Edzer Pebesma <
>>> edzer.pebesma using uni-muenster.de>
>>> wrote:
>>>
>>> > Without sharing a (minimal) reproducible example, it is unlikely that
>>> > someone else can help you find out whether this points to a problem in
>>> > your data, or in the software.
>>> >
>>> > On 10/15/19 2:31 PM, argunaw . wrote:
>>> > >   When I run this, I get the following error:
>>> > >
>>> > > *Error in CPL_sfc_from_wkt(x) : OGR error*
>>> > >
>>> > > When I run it on my data, I get the same error.
>>> > >
>>> > > On Tue, Oct 15, 2019 at 2:16 PM Edzer Pebesma
>>> > > <edzer.pebesma using uni-muenster.de <mailto:edzer.pebesma using uni-muenster.de
>>> >>
>>> > > wrote:
>>> > >
>>> > >     You may try something along these lines:
>>> > >
>>> > >     # read data.frame with read.csv; here, we create an example by
>>> hand:
>>> > >     df = data.frame(
>>> > >                     a = 1:3, b = 3:1, geom = c("LINESTRING(0 0, 1
>>> 1)",
>>> > >     "LINESTRING(1 1,2
>>> > >     2)", "LINESTRING(5 5,6 6)")
>>> > >     )
>>> > >
>>> > >     library(sf)
>>> > >     sf = st_sf(df, geom = st_as_sfc(df$geom))
>>> > >     sf
>>> > >
>>> > >
>>> > >     On 10/15/19 1:58 PM, argunaw . wrote:
>>> > >     > I'm not sure how it was exported from postgis- the person who
>>> gave
>>> > >     me the
>>> > >     > file wasn't the one who downloaded it unfortunately.
>>> > >     >
>>> > >     > The file is a line file of roads. The files main columns are
>>> road
>>> > ID
>>> > >     > numbers (type integer) and the geometry column (type geometry,
>>> > >     long strong
>>> > >     > of letters and numbers). Only the IT admins where I am have the
>>> > >     postgis
>>> > >     > load/import tools in the pgadmin/sql interface. The rest of us
>>> can
>>> > >     download
>>> > >     > from sql and create new tables from other sql databases, but
>>> not
>>> > >     create a
>>> > >     > new table from a csv file.
>>> > >     >
>>> > >     > On Tue, Oct 15, 2019 at 1:11 PM Alex Mandel
>>> > >     <tech_dev using wildintellect.com <mailto:tech_dev using wildintellect.com>>
>>> > >     > wrote:
>>> > >     >
>>> > >     >> On 10/15/19 8:43 AM, argunaw . wrote:
>>> > >     >>> Hello Everyone,
>>> > >     >>>
>>> > >     >>> I have a csv file with a postgis "geometry" column. I've been
>>> > >     trying to
>>> > >     >>> import it in to R as a SF file, with the goal of exporting
>>> it to
>>> > a
>>> > >     >> postgis
>>> > >     >>> database, but to no avail. I've used the following methods:
>>> > >     >>>
>>> > >     >>> 1. file <- st_read("name.csv", stringsAsFactors=F,
>>> > >     geometry_column=geom)
>>> > >     >>>
>>> > >     >>> 2. file <- fread("name.csv", headers=True)
>>> > >     >>>     file <- st_as_sf(file)
>>> > >     >>>
>>> > >     >>> How can I import a csv with a postgis "geometry" column in
>>> to R
>>> > as a
>>> > >     >>> spatial/SF object?
>>> > >     >>>
>>> > >     >>>       [[alternative HTML version deleted]]
>>> > >     >>>
>>> > >     >>> _______________________________________________
>>> > >     >>> R-sig-Geo mailing list
>>> > >     >>> R-sig-Geo using r-project.org <mailto:R-sig-Geo using r-project.org>
>>> > >     >>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>> > >     >>>
>>> > >     >>
>>> > >     >> Can you paste an example somewhere, is it binary data or some
>>> > kind of
>>> > >     >> plain text column? Do you know how it was exported from
>>> Postgis?
>>> > >     >>
>>> > >     >> If it's a dump from a postgis database did you try loading the
>>> > table
>>> > >     >> directly to postgis with it's own load/import, or sql tools?
>>> > >     >>
>>> > >     >> Thanks,
>>> > >     >> Alex
>>> > >     >>
>>> > >     >
>>> > >     >       [[alternative HTML version deleted]]
>>> > >     >
>>> > >     > _______________________________________________
>>> > >     > R-sig-Geo mailing list
>>> > >     > R-sig-Geo using r-project.org <mailto:R-sig-Geo using r-project.org>
>>> > >     > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>> > >     >
>>> > >
>>> > >     --
>>> > >     Edzer Pebesma
>>> > >     Institute for Geoinformatics
>>> > >     Heisenbergstrasse 2, 48151 Muenster, Germany
>>> > >     Phone: +49 251 8333081
>>> > >     _______________________________________________
>>> > >     R-sig-Geo mailing list
>>> > >     R-sig-Geo using r-project.org <mailto:R-sig-Geo using r-project.org>
>>> > >     https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>> > >
>>> >
>>> > --
>>> > Edzer Pebesma
>>> > Institute for Geoinformatics
>>> > Heisenbergstrasse 2, 48151 Muenster, Germany
>>> > Phone: +49 251 8333081
>>> >
>>>
>>>         [[alternative HTML version deleted]]
>>>
>>> _______________________________________________
>>> R-sig-Geo mailing list
>>> R-sig-Geo using r-project.org
>>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>>
>>

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