[R-sig-Geo] FW: GWAR - R

[Inaki Sagarzazu]

Great thanks.

I understand you can't it a linear model with missing info, but you can stillmake valid predictions. I thought from your previous email that this wasn't the case with gwr, thus my question.

Thanks

Inaki

On 25 Sep 2011, at 11:37, "Roger Bivand" <Roger.Bivand at nhh.no> wrote:

> On Sun, 25 Sep 2011, Inaki Sagarzazu wrote:
> 
>> Hi Roger
>> 
>> Thanks for your response. I am not sure why there can't be polygons with 
>> missing info. Is it something with the model or the estimation?
> 
> You cannot fit a linear model with missing info either, those cases get 
> dropped.
> 
>> 
>> Also, How can I drop the NA's from a shape file in R? I've tried but 
>> can't seem to be able to do it.
>> 
> 
> Assuming that the data only contain variables that are relevant for the 
> model, create a logical vector and subset in the usual way:
> 
> cc <- complete.cases(as(myshp, "data.frame"))
> myshp_cc <- myshp[cc,]
> 
> If there are other unused variables with NAs that may lead you to drop 
> more observations than necessary, create a new object with only the 
> relevant columns first:
> 
> names(myshp0)
> myshp <- myshp0[, c(1,3,5,7)]
> 
> if c(1,3,5,7) are the variables you want - you can use names in a vector 
> too.
> 
> Hope this helps,
> 
> Roger
> 
>> Thanks
>> 
>> Inaki
>> 
>> On 24 Sep 2011, at 08:27, "Roger Bivand" <Roger.Bivand at nhh.no> wrote:
>> 
>>> On Thu, 22 Sep 2011, Inaki Sagarzazu wrote:
>>> 
>>>> 
>>>> Hi,
>>>> 
>>>> I am trying to use gwr in R but I'm having problems because some of my
>>>> polygons have missing values (NA) for the variables of interest. Do you
>>>> have any suggestions on how to solve this?
>>> 
>>> If data is missing in the response or covariates, all bets are off. You
>>> could drop those observations, or incomplete variables. You could try to
>>> impute the values, but then standard results would not hold downstream.
>>> 
>>> Roger
>>> 
>>>> 
>>>> thanks
>>>> 
>>>> ---------------------------------------------------------------------------------------------------------------
>>>> Iñaki Sagarzazu, PhD
>>>> Research Officer
>>>> Nuffield College
>>>> University of Oxford
>>>> OX1 1NF Oxford
>>>> United Kingdom
>>>> 
>>>> Office: 44 (0) 1 865 614990
>>>> Inaki.Sagarzazu at nuffield.ox.ac.uk
>>>> http://www.inaki-sagarzazu.com
>>>> 
>>>> _______________________________________________
>>>> R-sig-Geo mailing list
>>>> R-sig-Geo at r-project.org
>>>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>>> 
>>> 
>>> --
>>> 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