[R] maptools package

[Jon Olav Skoien]

On 11/10/2010 11:27 PM, Aleksandr Andreev wrote:
> OK, that loads the shape file.
>
> But now when I do:
>
> submap<- subset(spb, as.character(spb$Name) == 'Vasilevsky Island')
>
> the submap still has the whole city, not just the subset. Is there now
> a different way of extracting a subset from a map?
I have never used subset with shape files, maybe you can try the following?
submap <- spb[spb$Name == "Vasilevsky Island",]
This usually works if spb is a SpatialPolygonsDataFrame.

Cheers,
Jon

> A
>
> 2010/11/10 Phil Spector<spector at stat.berkeley.edu>:
>> Aleksandr -
>>    What happens when you use
>>
>> library(maptools)
>> spb = readShapePoly('/home/sasha/Documents/maps/spb.shp')
>>
>>                                         - Phil Spector
>>                                          Statistical Computing Facility
>>                                          Department of Statistics
>>                                          UC Berkeley
>>                                          spector at stat.berkeley.edu
>>
>>
>>
>> On Wed, 10 Nov 2010, Aleksandr Andreev wrote:
>>
>>> A few years back, I wrote some code to plot maps with the maptools
>>> package. Now I am trying to reproduce my results, only to find out
>>> that maptools has been updated and my code no longer works.
>>>
>>> I've been able to fix the first part of it by forcing
>>> spb<- maptools:::read.shape("/home/sasha/Documents/maps/spb.shp")
>>>
>>> (as read.shape has been deprecated)
>>>
>>> but now when I do
>>> plot(spb, xlab="Longitude", ylab="Latitude", main="Map of St
>>> Petersburg, Russia")
>>>
>>> I get the message
>>> Error in xy.coords(x, y, xlabel, ylabel, log) :
>>>   'x' is a list, but does not have components 'x' and 'y'
>>>
>>> What's the new syntax that I'm supposed to use?
>>>
>>> I'm using R version 2.12.0 (2010-10-15) on x86_64-pc-linux-gnu (64-bit)
>>>
>>> Thanks,
>>>
>>> ------------------------
>>> Aleksandr Andreev
>>> Graduate Student - Department of Economics
>>> University of North Carolina at Chapel Hill
>>> Mobile: +1 303 507 93 88
>>> Skype: typiconman
>>>
>>> ______________________________________________
>>> R-help at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide
>>> http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>