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

[Ista Zahn]

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)
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
>



-- 
Ista Zahn
Graduate student
University of Rochester
Department of Clinical and Social Psychology
http://yourpsyche.org