[R] 3D density estimation with library sm - no estimate returned

From: Gregory Jefferis <gsxej2_at_cam.ac.uk>
Date: Sat 28 May 2005 - 00:05:56 EST


Dear List,

I have been trying to use library sm to do density estimation on a 3D dataset. I am using the current MacOS X binary of sm from CRAN. If I do this on a 2D dataset, sm.density returns a list including the component "estimate" which contains the density estimate over a uniform grid. When doing this with 3D data, although I get a nice plot (even when I don't ask for one), the returned list only contains the original data (see below). It would appear that the internal function sm.density.3d is returning NULL. Have I misunderstood what should be returned? Is this a platform specific problem? Can someone suggest a fix or an alternative library for my application? Very many thanks for your help,

Greg Jefferis.

> R.version

         _
platform powerpc-apple-darwin7.9.0

arch     powerpc   
os       darwin7.9.0

system powerpc, darwin7.9.0
status Patched
major    2         
minor    1.0       
year     2005      
month    05        
day      12        

language R

> library(sm)
> str(sm.density(matrix(rnorm(300),ncol=3),display="none")) List of 2
$ data:List of 3

  ..$ x    : num [1:100, 1:3]  0.9470 -1.5112  1.0589 -0.0884 -0.1900 ...
  .. ..- attr(*, "dimnames")=List of 2
  .. .. ..$ : NULL
  .. .. ..$ : chr [1:3] "" "" ""
  ..$ nbins: num 0
  ..$ freq : num [1:100] 1 1 1 1 1 1 1 1 1 1 ...

$ call: language sm.density(x = matrix(rnorm(300), ncol = 3), display =
"none")
> str(sm.density(matrix(rnorm(200),ncol=2),display="none")) List of 10
$ eval.points: num [1:50, 1:2] -2.67 -2.57 -2.47 -2.38 -2.28 ...
  ..- attr(*, "dimnames")=List of 2
  .. ..$ : NULL
  .. ..$ : chr [1:2] "xnew" "ynew"

$ estimate : num [1:50, 1:50] 3.76e-05 5.10e-05 7.57e-05 1.22e-04
2.05e-04 ...
$ h : Named num [1:2] 0.414 0.512
  ..- attr(*, "names")= chr [1:2] "" ""
$ h.weights : num [1:100] 1 1 1 1 1 1 1 1 1 1 ...
$ weights : num [1:100] 1 1 1 1 1 1 1 1 1 1 ...
$ se : num [1:50, 1:50] 0.0306 0.0306 0.0306 0.0306 0.0306 ...
$ upper : num [1:50, 1:50] 0.00454 0.00468 0.00489 0.00523 0.00571 ...
$ lower : num [1:50, 1:50] 0 0 0 0 0 0 0 0 0 0 ...
$ data :List of 3
  ..$ x    : num [1:100, 1:2] -0.694 -0.192  0.149 -0.718 -0.357 ...
  .. ..- attr(*, "dimnames")=List of 2
  .. .. ..$ : NULL
  .. .. ..$ : chr [1:2] "" ""
  ..$ nbins: num 0
  ..$ freq : num [1:100] 1 1 1 1 1 1 1 1 1 1 ...

$ call : language sm.density(x = matrix(rnorm(200), ncol = 2),
display = "none")
>
-- 
Gregory Jefferis, PhD                               and:
Research Fellow
Department of Zoology                               St John's College
Downing Street                                      Cambridge
Cambridge, CB2 3EJ                                  CB2 1TP

Tel: +44 (0)1223 336683                             +44 (0)1223 339899
Fax: +44 (0)1223 336676                             +44 (0)1223 337720

gsxej2@cam.ac.uk

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Received on Sat May 28 00:13:37 2005

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