Gregory Jefferis
2005-May-27 14:05 UTC
[R] 3D density estimation with library sm - no estimate returned
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 at cam.ac.uk