[R] stringdot

[Nair, Murlidharan T]

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 <- ksvm(Class~.,data=promotergene,kernel="rbfdot",C=10,cross=5)# works fine with the rbf kernel


gene.string <- ksvm(Class~.,data=promotergene,kernel="stringdot",C=10,cross=5) # this give the following error

#Error in match.arg(kernel, c("rbfdot", "polydot", "tanhdot", "vanilladot",  :
# 'arg' should be one of “rbfdot”, “polydot”, “tanhdot”, “vanilladot”, “laplacedot”, “besseldot”, “anovadot”, “splinedot”, “matrix”



What am I doing wrong here?

Thanks ../Murli