svmlight {klaR} | R Documentation |
Function to call SVMlight from R for classification. Multiple group classification is done with the one-against-rest partition of data.
svmlight(x, ...) ## Default S3 method: svmlight(x, grouping, temp.dir = NULL, pathsvm = NULL, del = TRUE, type = "C", class.type = "oaa", svm.options = NULL, prior = NULL, out = FALSE, ...) ## S3 method for class 'data.frame': svmlight(x, ...) ## S3 method for class 'matrix': svmlight(x, grouping, ..., subset, na.action = na.fail) ## S3 method for class 'formula': svmlight(formula, data = NULL, ..., subset, na.action = na.fail)
x |
matrix or data frame containing the explanatory variables
(required, if formula is not given). |
grouping |
factor specifying the class for each observation
(required, if formula is not given). |
formula |
formula of the form groups ~ x1 + x2 + ... .
That is, the response is the grouping factor and the right hand side specifies the (non-factor) discriminators. |
data |
Data frame from which variables specified in formula are preferentially to be taken. |
temp.dir |
directory for temporary files. |
pathsvm |
Path to SVMlight binaries (required, if path is unknown by the OS). |
del |
Logical: whether to delete temporary files |
type |
Perform "C" =Classification or "R" =Regression |
class.type |
Multiclass scheme to use. See details. |
svm.options |
Optional parameters to SVMlight.
For further details see: “How to use” on http://svmlight.joachims.org/. |
prior |
A Priori probabilities of classes. |
out |
Logical: whether SVMlight output ahouild be printed on console (only for Windows OS.) |
subset |
An index vector specifying the cases to be used in the training sample. (Note: If given, this argument must be named.) |
na.action |
specify the action to be taken if NA s are
found. The default action is for the procedure to fail. An
alternative is na.omit , which leads to rejection of cases with
missing values on any required variable. (Note: If given, this
argument must be named.) |
... |
Function to call SVMlight from R for classification (type="C"
).
SVMlight is an implementation of Vapnik's Support Vector Machine. It
is written in C by Thorsten Joachims. On the homepage (see below) the
source-code and several binaries for SVMlight are available. If more
then two classes are given the SVM is learned by the one-against-all
scheme (class.type="oaa"
). That means that each class is trained against the other K-1
classes. The class with the highest decision function in the SVM
wins. So K SVMs have to be learned.
If class.type="oao"
each class is tested against every other and the final class is elected
by a majority vote.
If type="R"
a SVM Regression is performed.
A list containing the function call and the result of SVMlight.
SVMlight (http://svmlight.joachims.org/) must be installed before using this interface.
Karsten Luebke, luebke@statistik.tu-dortmund.de, Andrea Preusser
## Not run: ## Only works if the svmlight binaries are in the path. data(iris) x <- svmlight(Species ~ ., data = iris) ## Using RBF-Kernel with gamma=0.1: data(B3) x <- svmlight(PHASEN ~ ., data = B3, svm.options = "-t 2 -g 0.1") ## End(Not run)