Displaying 20 results from an estimated 4000 matches similar to: "Confidence interval for Support Vector Regression"
2009 Nov 29
2
kernlab's ksvm method freeze
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,
2009 Apr 28
1
kernlab - custom kernel
hi,
I am using R's "kernlab" package, exactly i am doing classification using
ksvm(.) and predict.ksvm(.).I want use of custom kernel. I am getting some
error.
# Following R code works (with promotergene dataset):
library("kernlab")
s <- function(x, y) {
sum((x*y)^1.25)
}
class(s) <- "kernel"
data("promotergene")
gene <- ksvm(Class ~ .,
2011 Aug 26
1
kernlab: ksvm() bug?
Hello all,
I'm trying to run a gird parameter search for a svm.
Therefore I'M using the ksvm function from the kernlab package.
----
svp <- ksvm(Ktrain,ytrain,type="nu-svc",nu=C)
----
The problem is that the optimization algorithm does not return
for certain parameters.
I tried to use setTimeLimit() but that doesn't seem to help.
I suspect that ksvm() calls c code that
2006 Nov 24
1
How to find AUC in SVM (kernlab package)
Dear all,
I was wondering if someone can help me. I am learning SVM for
classification in my research with kernlab package. I want to know about
classification performance using Area Under Curve (AUC). I know ROCR
package can do this job but I found all example in ROCR package have
include prediction, for example, ROCR.hiv {ROCR}. My problem is how to
produce prediction in SVM and to find
2008 Jun 25
1
stringdot
Hi!!
I am trying to figure out how to use the string kernel "stringdot" in kernlab.
k <- function(x,y) {
(sum(x*y) +1)*exp(-0.001*sum((x-y)^2))
}
class(k) <- "kernel"
data(promotergene)
## train svm using custom kernel
gene.k <- ksvm(Class~.,data=promotergene,kernel=k,C=10,cross=5) # works fine in this case
gene.rbf <-
2012 Aug 19
1
kernlab | ksvm error
Dear list,
I am using the ksvm function from kernlab as follows:
(1) learning
> svm.pol4 <- ksvm(class.labs ~ ., data = train.data, prob.model = T, scale
= T, kernel = "polydot")
(2) prediction
> svm.pol.prd4 <- predict(svm.pol4, train.data, type = "probabilities")[,2]
But unfortunately, when calling the prediction, once in every 10s of times
(using the exact
2012 Nov 15
1
Can't see what i did wrong..
with
pred.pca<-predict(splits[[i]]$pca,trainingData at samples)[,1:nPCs]
dframe<-as.data.frame(cbind(pred.pca,class=isExplosive(trainingData,2)));
results[[i]]$classifier<-ksvm(class~.,data=dframe,scaled=T,kernel="polydot",type="C-svc",
C=C,kpar=list(degree=degree,scale=scale,offset=offset),prob.model=T)
and a degree of 5 i get an error of 0 reported by the ksvm
2009 Dec 25
2
Help with SVM package Kernlab
Hi useR's,
I am resending this request since I got no response for my last post and I
am new to the list so pardon me if I am violating the protocol.
I am trying to use the "Kernlab" package for training and prediction using
SVM's. I am getting the following error when I am trying to use the predict
function:
> predictSvm = predict(modelforSVM, testSeq);
Error in
2009 Oct 23
1
Data format for KSVM
Hi,
I have a process using svm from the e1071 library. it works.
I want to try using the KSVM library instead. The same data used wiht
e1071 gives me an error with KSVM.
My data is a data.frame.
sample code:
svm_formula <- formula(y ~ a + B + C)
svm_model <- ksvm(formula, data=train_data, type="C-svc",
kernel="rbfdot", C=1)
I get the following error:
2012 Nov 29
1
Help with this error "kernlab class probability calculations failed; returning NAs"
I have never been able to get class probabilities to work and I am relatively new to using these tools, and I am looking for some insight as to what may be wrong.
I am using caret with kernlab/ksvm. I will simplify my problem to a basic data set which produces the same problem. I have read the caret vignettes as well as documentation for ?train. I appreciate any direction you can give. I
2009 Oct 04
3
error installing/compiling kernlab
Hi everybody,
I''m using R on a 64-bit Ubuntu 9.04 (Jaunty). I prefer to install R
packages from source, even if they are available in Synaptic. The
problem is that I can''t install/compile kernlab. Everything works fine
until it gets to the lazy loading part:
** preparing package for lazy loading
Creating a new generic function for "terms" in "kernlab"
2005 Jul 07
1
Kernlab: problem with small datasets
Hi,
I found a small problem with kernlab. The problem, I think, is that the
3-fold cross-validation performed to estimate probabilities is not
class-balanced, so the classifier could find empty classes.
The following example (maybe a little forced) show the error:
data(glass)
set.seed(1)
2011 Aug 20
1
How to abort function execution after x-seconds
Hello all,
I'm running a parameter grid optimization ( ksvm, kernlab package) and
the optimizer
seems not to converge for certain parameters and stays in a infinity loop.
Would it be possible to abort the execution after x-seconds and continue
with the next parameter set? Which R function do need to use to
accomplish this?
I had a look at, try() etc. but they didn't seem so fit my
2007 Aug 14
0
kernlab ksvm() cross-validation prediction response vector
Hello,
I would like to know, whether for the support vector classification function ksvm()
the response values stored in object at ymatrix are cross validated outputs/predictions:
Example code from package kernlab, function ksvm:
library(kernlab)
## train a support vector machine
filter <- ksvm(type~.,data=spam,kernel="rbfdot",kpar=list(sigma=0.05),C=5,cross=3)
filter
filter at
2013 Nov 15
1
Inconsistent results between caret+kernlab versions
I'm using caret to assess classifier performance (and it's great!). However, I've found that my results differ between R2.* and R3.* - reported accuracies are reduced dramatically. I suspect that a code change to kernlab ksvm may be responsible (see version 5.16-24 here: http://cran.r-project.org/web/packages/caret/news.html). I get very different results between caret_5.15-61 +
2007 Oct 30
0
kernlab/ ksvm: class.weights & prob.model in binary classification
Hello list,
I am faced with a two-class classification problem with highly asymetric
class sizes (class one: 99%, class two: 1%).
I'd like to obtain a class probability model, also introducing available
information on the class prior.
Calling kernlab/ksvm with the line
>
ksvm_model1<-ksvm(as.matrix(slides), as.factor(Class), class.weights= c("0"
=99, "1" =1),
2012 Aug 27
0
kernlab`s custom kernel of ksvm freeze
Hello, together
I'm trying to use user defined kernel. I know that kernlab offer user
defined kernel(custom kernel functions) in R.
I used data spam including package kernlab.
(number of variables=58 number of examples =4061)
i'm user defined kernel's form,
kp=function(d,e){
as=v*d
bs=v*e
cs=as-bs
cs=as.matrix(cs)
exp(-(norm(cs,"F")^2)/2)
}
2007 Jul 02
1
QP for solving Support Vector Regression
Dear R users,
I'm trying to run the Support Vector Regression by a general quadratic programming function like ipop ( ) in kernlab or solve.QP ( ) in quadprog packages.
Since they are general, their application in Support Vector Regression can lead to misunderstanding, particularly when constructing matrices. Even their examples are general and applied in Support Vector
2010 Sep 24
0
kernlab:ksvm:eps-svr: bug?
Hi,
A. In a nutshell:
The training error, obtained as "error (ret)", from the return value
of a ksvm () call for a eps-svr model is (likely) being computed
wrongly. "nu-svr" and "eps-bsvr" suffer from this as well.
I am attaching three files: (1) ksvm.R from the the kernlab package,
un-edited, (2) ksvm_eps-svr.txt: (for easier reading) containing only
eps-svr
2011 May 28
0
how to train ksvm with spectral kernel (kernlab) in caret?
Hello all,
I would like to use the train function from the caret package to
train a svm with a spectral kernel from the kernlab package. Sadly
a svm with spectral kernel is not among the many methods in caret...
using caret to train svmRadial:
------------------
library(caret)
library(kernlab)
data(iris)
TrainData<- iris[,1:4]
TrainClasses<- iris[,5]
set.seed(2)