[R-sig-Geo] Missing local R-squared and residuals in gwr output

[Roger Bivand]

On Fri, 4 May 2012, Maximilian Sproß wrote:

> Dear r-sig-geo list!
>
> I run gwr on a multi-node cluster(on 64 slots). In the gwr output (slot
> "SDF"), the gwr residuals and the local R-squared are missing. When
> performing the same model on the local machine, these components are
> included. Unfortunately, the calculation in this way takes about 5 days
> instead of few hours when using the cluster.
>
> Perhaps, that problem arises due to the argument "fit.points", which has
> to be passed if the local coefficient estimates should be made on a
> multi node cluster.
>
> Does anyone have an idea how to solve that problem with the missing
> local R-squared and residuals if the gwr is calculated on a cluster?

The understanding for use on a cluster was that the data points and the 
fit points are different, so there is no observed dependent variable at 
the fit point, hence no local R2. I've added logic in the code that checks 
for equality between the fit and data points, and this for me resolves the 
problem, but may break other things. I've committed to R-forge, project 
rspatial, module spgwr. The source tarball and binary packages should be 
available later this evening European time from:

https://r-forge.r-project.org/R/?group_id=1014

Could you please try it out, and report back? I should also migrate spgwr 
from snow to parallel before I release it.

Best wishes,

Roger

>
>
> Thank you very much in advance!
>
> Kind regards,
>
> Max
>
>
> selected R-code:
>
> ### gwr on local machine:
>
> gwr_50 <-
> gwr(hef at data$DIF~hef at data$ELEVATION+hef at data$SKY+hef at data$SLOPE+hef at data$SOLAR,
> data=hef, bandwidth=50, gweight=gwr.Gauss)
>
>
> # part of the  str(gwr_50) output...
>
>
> List of 11
>  $ SDF      :Formal class 'SpatialPointsDataFrame' [package "sp"] with 5 slots
>   .. ..@ data       :'data.frame':	286288 obs. of  9 variables:
>   .. .. ..$ sum.w      : num [1:286288] 2009 2003 2091 2089 2086 ...
>   .. .. ..$ (Intercept): num [1:286288] -28.7 -28.5 -29.9 -29.7 -29.5 ...
>   .. .. ..$ elevation  : num [1:286288] 0.0139 0.0138 0.014 0.014 0.014 ...
>   .. .. ..$ sky        : num [1:286288] -0.153 -0.155 -0.146 -0.148 -0.149 ...
>   .. .. ..$ slope      : num [1:286288] -2.58 -2.61 -2.42 -2.45 -2.48 ...
>   .. .. ..$ solar      : num [1:286288] -0.00139 -0.00136 -0.0015 -0.00147 -0.00144 ...
>   .. .. ..$ gwr.e      : num [1:286288] -0.461 -0.683 -0.5987 -0.2692 0.0406 ...
>   .. .. ..$ pred       : num [1:286288] 0.806 0.833 0.507 0.514 0.576 ...
>   .. .. ..$ localR2    : num [1:286288] 0.621 0.618 0.638 0.635 0.632 ...
>
>
>
>
> ### gwr on cluster :
>
> cl <- makeCluster(32, type="MPI")
>
> coords <- coordinates(hef)
>
> gw <-
> gwr(hef at data$DIF~hef at data$ELEVATION+hef at data$SKY+hef at data$SLOPE+hef at data$SOLAR,
> data=hef, bandwidth=50, gweight=gwr.Gauss,fit.points=coords,
> hatmatrix=FALSE, cl=cl)
>
> # part of the  str(gwr_50) output...
>
> List of 11
>  $ SDF      :Formal class 'SpatialPointsDataFrame' [package "sp"] with 5 slots
>   .. ..@ data       :'data.frame':	286288 obs. of  6 variables:
>   .. .. ..$ sum.w      : num [1:286288] 1 1 1 1 1 ...
>   .. .. ..$ (Intercept): num [1:286288] 12541 1970 2057 -1505 -1030 ...
>   .. .. ..$ elevation  : num [1:286288] -3.891 -0.602 -0.738 0.465 0.309 ...
>   .. .. ..$ sky        : num [1:286288] -0.954 -0.425 3.714 0.159 0.152 ...
>   .. .. ..$ slope      : num [1:286288] 62.19 NA -27.21 1.95 16.03 ...
>   .. .. ..$ solar      : num [1:286288] NA NA NA NA 0.042 ...
>
>
>
>
> 	[[alternative HTML version deleted]]
>
> _______________________________________________
> 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