Missing local R-squared and residuals in gwr output

--
Mag. J. Maximilian Spro?
Institute of Geography, University of Innsbruck
Innrain 52
A-6020 INNSBRUCK

Tel. +43 (0)512 507 5413
web: http://www.uibk.ac.at/geographie/projects/lidar/



-----Urspr?ngliche Nachricht-----
Von: Roger Bivand [mailto:Roger.Bivand at nhh.no]
Gesendet: Mo 07.05.2012 14:48
An: Maximilian Spro?
Cc: r-sig-geo
Betreff: Re: [R-sig-Geo] Missing local R-squared and residuals in gwr output

On Mon, 7 May 2012, Maximilian Spro? wrote:

Dear Roger!

Thank you very much for your fast reply and work!

I'm not really an expert in HPC-computing, but i will try to report as goog
as i can.

I updated spgwr and started a job on the cluster which takes normally 1,5 h.
So far, it run for 5 hours, which indicates that the parallelization does not
work efficient anymore. The function makeCluster(64, type="MPI") worked fine.
Our cluster runs with openMPI.

Correct. I'll try to add back an option to use snow instead of parallel.

I tried out the new version but it seems still using parallel.

code:

gwr_50 <- gwr(hef at data$DIF~hef at data$ELEVATION+hef at data$SKY+hef at data$SLOPE+hef at data$SOLAR+factor(asp_fac), data=hef, bandwidth=50, gweight=gwr.Gauss,fit.points=coords, hatmatrix=FALSE, cl=cl)

Loading required package: parallel

Attaching package: 'parallel'

The following object(s) are masked from 'package:snow':

   clusterApply, clusterApplyLB, clusterCall, clusterEvalQ,
   clusterExport, clusterMap, clusterSplit, makeCluster, parApply,
   parCapply, parLapply, parRapply, parSapply, splitIndices,
   stopCluster

Max


When it reaches R-forge, its revision number will be > 1252.

Roger

In that context, i found on the CRAN Task view: High-Performance and Parallel
Computing with R the following:
"<http://www.dict.cc/englisch-deutsch/parallelization.html>Direct support in
R is starting with release 2.14.0 which includes a new package parallel
incorporating (slightly revised) copies of packages multicore and snow (*but
excluding MPI, PVM and NWS clusters*). Does the new parallel support works
still in the openMPI environment?

regards,

Max

fyi:

sessionInfo()
R version 2.14.0 (2011-10-31)
Platform: x86_64-unknown-linux-gnu (64-bit)

locale:
[1] LC_CTYPE=en_US       LC_NUMERIC=C         LC_TIME=en_US
[4] LC_COLLATE=en_US     LC_MONETARY=en_US    LC_MESSAGES=en_US
[7] LC_PAPER=C           LC_NAME=C            LC_ADDRESS=C
[10] LC_TELEPHONE=C       LC_MEASUREMENT=en_US LC_IDENTIFICATION=C

attached base packages:
[1] parallel  stats     graphics  grDevices utils     datasets  methods
[8] base

other attached packages:
[1] spgwr_0.6-15    spdep_0.5-45    coda_0.14-6     deldir_0.0-16
[5] maptools_0.8-10 foreign_0.8-46  nlme_3.1-102    MASS_7.3-16
[9] Matrix_1.0-1    lattice_0.20-0  boot_1.3-3      gstat_1.0-10
[13] spacetime_0.5-7 xts_0.8-2       zoo_1.7-6       sp_0.9-98
[17] snow_0.3-8      Rmpi_0.5-9

loaded via a namespace (and not attached):
[1] grid_2.14.0


On 05/05/2012 04:24 PM, Roger Bivand wrote:

On Fri, 4 May 2012, Maximilian Spro? 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 ...




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--
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