[R-sig-Geo] Problem with aggregating UScensus2000 FL data

[Roger Bivand]

On Mon, 1 Aug 2011, Ista Zahn wrote:

> Hi Roger,
>
> On Mon, Aug 1, 2011 at 2:38 PM, Roger Bivand <Roger.Bivand at nhh.no> wrote:
>> On Mon, 1 Aug 2011, Ista Zahn wrote:
>>
>>> Oops, I got the examples mixed up. The Alabama example works, the
>>> Florida example does not. I also should have given the version info,
>>> as this may well be version specific.
>>
>> You also need to provide the link to the data file, and the code prior to
>> what you show. The function county() is not defined anywhere, consequently
>> the attribute fields are nothing like tract boundaries such as those on:
>
> Sorry I wasn't clear. The data and the county function are in the
> UScensus2000 packages. Let me try again. A complete example leading to
> the error is
>
> library(UScensus2000)

Perhaps contact the package maintainer? It is very possible that the 
package ships with unclean topologies, isn't it? I'll try to look later.

Roger

> library(maptools)
> data(countyfips)
>
> tmp <- county(fips = gsub("^..", "",
> countyfips$fips[countyfips$acronym == "fl"]), state = "fl", level =
> "tract")
> dat <- as.data.frame(tmp)
> tmp.county <- unionSpatialPolygons(tmp, dat$county)
>
>>
>> http://www.census.gov/geo/www/cob/tr2000.html
>>
>> The lines do intersect (touch), and should not in a topologically correct
>> setting; the coordinates seem odd - what is the projection? Did you run
>> checkPolygonsHoles() first?
>
> I would if I could figure out how to convert a SpatialPolygons object
> to a Polygons object... I'm just getting started with sp.
>
> Thanks,
> Ista
>
>>
>> Roger
>>
>>>
>>> R version 2.13.1 (2011-07-08)
>>> Platform: i386-pc-mingw32/i386 (32-bit)
>>>
>>> locale:
>>> [1] LC_COLLATE=English_United States.1252
>>> [2] LC_CTYPE=English_United States.1252
>>> [3] LC_MONETARY=English_United States.1252
>>> [4] LC_NUMERIC=C
>>> [5] LC_TIME=English_United States.1252
>>>
>>> attached base packages:
>>> [1] grid      stats     graphics  grDevices utils     datasets  methods
>>> [8] base
>>>
>>> other attached packages:
>>> [1] rgeos_0.1-8             stringr_0.5             quadprog_1.5-4
>>> [4] directlabels_1.3        UScensus2000_1.00       gpclib_1.5-1
>>> [7] UScensus2000cdp_0.03    UScensus2000blkgrp_0.03 UScensus2000tract_0.03
>>> [10] rgdal_0.7-1             maptools_0.8-9          lattice_0.19-30
>>> [13] sp_0.9-84               foreign_0.8-45          ggplot2_0.8.9
>>> [16] proto_0.3-9.2           reshape_0.8.4           plyr_1.5.2
>>>
>>> loaded via a namespace (and not attached):
>>> [1] digest_0.5.0 tools_2.13.1
>>>>
>>>
>>> On Mon, Aug 1, 2011 at 11:09 AM, Ista Zahn <izahn at psych.rochester.edu>
>>> wrote:
>>>>
>>>> Hi all,
>>>> I am trying to aggregate the UScensus data for Florida up to the zip
>>>> code level using unionSpatialPolygons from the maptools package. This
>>>> works for other states, but not for Florida:
>>>>
>>>> ## Works
>>>> tmp <- county(fips = gsub("^..", "",
>>>> countyfips$fips[countyfips$acronym == "fl"]), state = "fl", level =
>>>> "tract")
>>>> dat <- as.data.frame(tmp)
>>>> tmp.county <- unionSpatialPolygons(tmp, dat$county)
>>>>
>>>> ## Returns error
>>>> tmp <- county(fips = gsub("^..", "",
>>>> countyfips$fips[countyfips$acronym == "al"]), state = "al", level =
>>>> "tract")
>>>> dat <- as.data.frame(tmp)
>>>> tmp.county <- unionSpatialPolygons(tmp, dat$county)
>>>> Error in TopologyFunc(groupID(spgeom[ids[[i]]], id[ids[[i]]]),
>>>> names(ids)[i],  :
>>>>  TopologyException: found non-noded intersection between LINESTRING
>>>> (-0.640183 0.433522, -0.678743 0.433456) and LINESTRING (-0.678743
>>>> 0.433456, -0.677839 0.434367) at -0.678743 0.433456
>>>>
>>>> Does anyone have a suggestion about how to do this?
>>>>
>>>> Thanks!
>>>>
>>>> Ista
>>>> --
>>>> Ista Zahn
>>>> Graduate student
>>>> University of Rochester
>>>> Department of Clinical and Social Psychology
>>>> http://yourpsyche.org
>>>>
>>>
>>>
>>>
>>>
>>
>> --
>> Roger Bivand
>> Department of Economics, NHH Norwegian School of Economics,
>> Helleveien 30, N-5045 Bergen, Norway.
>> voice: +47 55 95 93 55; fax +47 55 95 95 43
>> e-mail: Roger.Bivand at nhh.no
>>
>
>
>
>

-- 
Roger Bivand
Department of Economics, NHH Norwegian School of Economics,
Helleveien 30, N-5045 Bergen, Norway.
voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no