[R] kernlab's ksvm method freeze

Heiko Strathmann heiko.strathmann at googlemail.com
Mon Nov 30 21:49:14 CET 2009


Hello again,

i got this message from the maintainer:


Am Montag, den 30.11.2009, 11:22 +0100 schrieb Heiko Strathmann:
> Ok, i reported it.
> thanks for trying it out again.
> 
> Am 30. November 2009 11:06 schrieb Uwe Ligges
> <ligges at statistik.tu-dortmund.de>:
>         My apologies, that must have been a copy&paste error and the
>         essential argument got lost. I can reproduce it now under
>         R-2.10.0 both Windows and Linux.
>         
>         Please report your findings to the package maintainer who
>         might be able to debug this under Linux (probably easier than
>         under Windows).
>         
>         Best,
>         
>         
>         Uwe Ligges
>         
>         
>         
>         
>         
>         
>         Heiko Strathmann wrote:
>                 I tried out the code you wrote, it also works for me,
>                 but it lacks a
>                 parameter i use in my code.
>                 
>                 The problem (at this computer) seems to be this
>                 "cross"-parameter of
>                 ksvm - if I, for example, add the parameter cross=10,
>                 i get the old
>                 problem:
>                 
>                 library("kernlab")
>                 load("freeze_workspace.RDATA")
>                 replicate(10, ksvm(kernel="matrix", kernelMatrix,
>                 trainingDataYs, type="C-svc", C=2, cross=10))
>                 
>                 gets me a frozen R process, CTRL-C does not work
>                 anymore, and the only thing left is to kill it.
>                 
>                 (for cross < 4, the thing still works)
>                 
>                 (I also just reinstalled my Ubuntu and R)
>                 
>                 Heiko Strathmann
>                 
>                 
>                 Am Sonntag, den 29.11.2009, 19:52 +0100 schrieb Uwe
>                 Ligges:
>                         Heiko Strathmann wrote:
>                                 Hello uwe,
>                                 Thanks for trying out.
>                                 the freeze happens after about 10 to
>                                 20 iterations. Did you try as many?
>                         I just tried again:
>                         
>                         library("kernlab")
>                         load("freeze_workspace.RDATA")
>                         replicate(100, ksvm(kernel="matrix",
>                         kernelMatrix, trainingDataYs, type="C-svc",
>                         C=2))
>                         
>                         and everything is still fine (same on Linux).
>                         
>                         Uwe Ligges
>                         
>                         
>                         
>                                 Am Sonntag, den 29.11.2009, 17:22
>                                 +0100 schrieb Uwe Ligges:
>                                         I just tried
>                                         
>                                         ksvm(kernel="matrix",
>                                         kernelMatrix, trainingDataYs,
>                                         type="C-svc", cross=10, C=2)
>                                         
>                                         several times on both
>                                         workspaces and both returned
>                                         some results after a couple of
>                                         seconds under the same
>                                         versions (R version 2.10.0 and
>                                         kernlab 0.9-9.) under Windows
>                                         XP.
>                                         
>                                         There mist be something else
>                                         going on...
>                                         
>                                         Best wishes,
>                                         Uwe Ligges
>                                         
>                                         
>                                         
>                                         
>                                         
>                                         Heiko Strathmann wrote:
>                                                 Hello again,
>                                                 
>                                                 the freeze seems to
>                                                 depend on the kernel
>                                                 matrix.
>                                                 With another kernel
>                                                 matrix of similiar
>                                                 size, gernerated with
>                                                 the same
>                                                 kernel, but on another
>                                                 dataset, there is no
>                                                 freeze.
>                                                 
>                                                 I have put a workspace
>                                                 with the working
>                                                 matrix and one with
>                                                 the freezing
>                                                 matrix online for
>                                                 testing (see old
>                                                 email)
>                                                 http://www-stud.uni-due.de/~sfhestra/
>                                                 
>                                                 In my eyes this
>                                                 behavior is really
>                                                 strange, and i have no
>                                                 clue, what to
>                                                 do to solve this.
>                                                 
>                                                 Regards,
>                                                 Heiko Strathmann
>                                                 
>                                                 Am Sonntag, den
>                                                 29.11.2009, 14:21
>                                                 +0100 schrieb Heiko
>                                                 Strathmann:
>                                                         Hello,
>                                                         
>                                                         I am using
>                                                         kernlab to do
>                                                         some binary
>                                                         classification
>                                                         on aminoacid
>                                                         strings.
>                                                         
>                                                         I am using a
>                                                         custom kernel,
>                                                         so i use the
>                                                         kernel="matrix" option of the
>                                                         ksvm method.
>                                                         
>                                                         My
>                                                         (normalized)
>                                                         kernel matrix
>                                                         is of size
>                                                         1309*1309, my
>                                                         results vector
>                                                         has the same
>                                                         length.
>                                                         
>                                                         I am using
>                                                         C-svc.
>                                                         
>                                                         My kernlab
>                                                         call is
>                                                         something
>                                                         similiar to
>                                                         this:
>                                                         
>                                                         ksvm(kernel="matrix", kernelMatrix, trainingDataYs, type="C-svc",
>                                                         cross=10, C=2)
>                                                         
>                                                         To this point,
>                                                         everything
>                                                         works fine.
>                                                         
>                                                         But now, i
>                                                         want to do a
>                                                         search for a
>                                                         good C
>                                                         Parameter, so
>                                                         I call the
>                                                         ksvm method
>                                                         multiple times
>                                                         in a loop,
>                                                         with changing
>                                                         parameters.
>                                                         This loop
>                                                         freezes after
>                                                         a few
>                                                         iterations.
>                                                         
>                                                         
>                                                         The following
>                                                         simple example
>                                                         also freezes
>                                                         after few
>                                                         iterations
>                                                         (the
>                                                         number
>                                                         varies). See
>                                                         that the ksvm
>                                                         call is always
>                                                         the same in
>                                                         every
>                                                         iteration:
>                                                         
>                                                         for (i in
>                                                         c(1:20)) {
>                                                         
>                                                          print(i)
>                                                         
>                                                          ksvm(kernel="matrix", kernelMatrix, trainingDataYs,
>                                                         type="C-svc",
>                                                         cross=10, C=2)
>                                                         }
>                                                         
>                                                         
>                                                         Does anybody
>                                                         have an idea
>                                                         what causes
>                                                         this? I am new
>                                                         to R and
>                                                         kernlab,
>                                                         perhaps i
>                                                         missed
>                                                         something?
>                                                         
>                                                         I put my
>                                                         workspace
>                                                         online, which
>                                                         contains the
>                                                         kernel matrix
>                                                         and the
>                                                         training
>                                                         labels. Simply
>                                                         load
>                                                         workspace,
>                                                         kernlab
>                                                         library and
>                                                         paste the
>                                                         example code
>                                                         to reproduce:
>                                                         http://www-stud.uni-due.de/~sfhestra/
>                                                         
>                                                         I am using R
>                                                         version 2.10.0
>                                                         and kernlab
>                                                         0.9-9.
>                                                         
>                                                         Thanks for
>                                                         your help!
>                                                         
>                                                         Regards,
>                                                         Heiko
>                                                         Strathmann
>                                                         
>                                                         
>                                                 ______________________________________________
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>                                 
>                 
>                 
>




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