Displaying 20 results from an estimated 3000 matches similar to: "Splitting dataset for Tuning Parameter with Cross Validation"
2007 Aug 01
1
RWeka cross-validation and Weka_control Parametrization
Hello,
I have two questions concerning the RWeka package:
1.) First question:
How can one perform a cross validation, -say 10fold- for a given data set and given model ?
2.) Second question
What is the correct syntax for the parametrization of e.g. Kernel classifiers interface
m1 <- SMO(Species ~ ., data = iris, control =
2012 Feb 10
1
Choosing glmnet lambda values via caret
Usually when using raw glmnet I let the implementation choose the
lambdas. However when training via caret::train the lambda values are
predetermined. Is there any way to have caret defer the lambda
choices to caret::train and thus choose the optimal lambda
dynamically?
--
Yang Zhang
http://yz.mit.edu/
2012 Oct 30
4
help - extract data using column names
hello , I am new user in R . I have datafile (class = data.frame) which has
825 columns with unique column name i want extract 200 selected column from
datafile how can I do this?
my datafile look like..
Mi RBN RBF nDB nX
3 2.6225979 0.53132756 -0.80599902 -1.4471864 -0.5705269
10 0.4818746 -1.72143092 -2.19579027 2.0118824 -0.5705269
12 2.8519611
2007 Dec 31
1
SVM error
Hi all,
I'm having this error, since I'm working with a data matrix I don't understand what's happening; I've tried several ways to solve this, even working with sparse matrix, but nothing seems to solve it, I've also tried svm (with a simple matrix 3*3 and still got the same error.
> dados<-read.table("b.txt",sep="",nrows=30000)
>
2012 Jun 15
1
Sugeestion about tuning of SVM
Dear list
I've a generic question about how to tune an SVM
I'm trying to classify with caret package some population data from a
case-control study . In each column of my matrix there are the SNP
genotypes , in each row there are the individuals.
I correctly splitted my total dataset in training(132 individuals) and test
(50 individuals) (respecting the total observed genotypic
2023 May 09
1
RandomForest tuning the parameters
Hi Sacha,
On second thought, perhaps this is more the direction that you want ...
X2 = cbind(X_train,y_train)
colnames(X2)[3] = "y"
regr2<-randomForest(y~x1+x2, data=X2,maxnodes=10, ntree=10)
regr
regr2
#Make prediction
predictions= predict(regr, X_test)
predictions2= predict(regr2, X_test)
HTH,
Eric
On Tue, May 9, 2023 at 6:40?AM Eric Berger <ericjberger at gmail.com>
2008 Feb 19
1
How to use BayesTree or RBF for predict
Hi all,
sorry for my english, but I don't speak yours language.
I'm trying to use bart() and rbf(). The package I'm using now is
"BayesTree" and "neural", respectively. I could create the models, but I
can't predict my test data.
Does anyone have such an experience? Any advice is appreciated!
Thank you in advanced!.
Andr?
--
View this message in
2012 May 30
1
caret() train based on cross validation - split dataset to keep sites together?
Hello all,
I have searched and have not yet identified a solution so now I am sending
this message. In short, I need to split my data into training, validation,
and testing subsets that keep all observations from the same sites together
? preferably as part of a cross validation procedure. Now for the longer
version. And I must confess that although my R skills are improving, they
are not so
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 <-
2005 Mar 17
1
kernlab sigest
hello,
I have the following problem setting parameter 'frac' in the sigest
function of the kernlab package.
## executing the ?sigest example:
library(kernlab)
data(spam)
srange <- sigest(type~.,data = spam)
## works fine...
## setting 'frac' explicitly
## (in this case even to the default of .25)
options(error=recover)
srange <- sigest(type~.,data = spam, frac = .25)
##
2010 May 08
2
String manipulation
Dear community,
I have a problem with a string conversion:
> text
[1] "" "and" "\xc1d\xe1m"
[4] "graphical" "interface" "MLP"
[7] "Nagy" "networks" "Networks"
[10] "neural" "Neural"
2008 Mar 02
2
listing components of an object
Is there a method to list the components of an object, instead of looking at the help for that method? Let me be more clear with an example
data(iris)
## tune `svm' for classification with RBF-kernel (default in svm),
## using one split for training/validation set
obj <- tune(svm, Species~., data = iris,
ranges = list(gamma = 2^(-1:1), cost = 2^(2:4)),
2011 Jan 07
2
Stepwise SVM Variable selection
I have a data set with about 30,000 training cases and 103 variable.
I've trained an SVM (using the e1071 package) for a binary classifier
{0,1}. The accuracy isn't great.
I used a grid search over the C and G parameters with an RBF kernel to
find the best settings.
I remember that for least squares, R has a nice stepwise function that
will try combining subsets of variables to find
2012 Aug 16
1
sum predictions by hand
Hi,
If I do a standard svm regression with e1071
x <- seq(0.1, 5, by = 0.05)
y <- log(x) + rnorm(x, sd = 0.2)
m <- svm(x, y)
we can do predict(m,x) to get the fitted values. But what if I wan tho get them by hand?
Seem to me like it should be
w = t(m$coefs)%*%m$SV
x.scaled = scale(x, m$x.scale[[1]], m$x.scale[[2]])
t(w %*% t(as.matrix(x.scaled))) - m$rho but this is wrong
If i
2004 Jun 29
1
wine and office 2000
Materiel : pc
OS : Linux (Mandrake 10.0)
Wine Version : 2004 02 13
I am studying Wine and when I want to install Office
2000 with Wine (from the cdrom or from the hard disk)
, the install crashes with this message : " error
1311. Cannot find the source file : D:\OFFCD1_2.CAB.
Check if this file exist and if you can access to it "
But this file doesn't exist !
the cdrom
2004 Dec 13
0
Problem tuning an SVM
Hi all -
(Re my previous question to the list, I managed to generate an ROC plot
for my SVM by ranking the data using the Decision.Values property.
Thanks for your responses)
I have now started tuning the SVM to get optimal parameters for the RBF
kernel and I ran into a problem. Whatever parameter ranges I specify, I
always get the same error values for all combinations of parameters it
2013 Feb 12
1
caret: Errors with createGrid for rf (randomForest)
When I try to crate a grid of parameters for training with caret I get
various errors:
------------------------------------------------------------
> my_grid <- createGrid("rf")
Error in if (p <= len) { : argument is of length zero
> my_grid <- createGrid("rf", 4)
Error in if (p <= len) { : argument is of length zero
> my_grid <-
2003 Nov 27
1
Winword keeps on running Configuration Setup
Hi,
I am currently running this version of wine
(wine-20031118-1rh9winehq.i386.rpm) on a RH9 OS.
I installed MS Word 2000 and everything went well. However, every time
I run MS Word, the configuration setup screen would appear. But after
that, it seems that MS Word runs OK.
There are also a number of messages coming out (see below).
Can anyone help me stop the configuration setup from
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),
2009 Oct 06
0
Kernlab: multidimensional targets in rvm(), ksvm(), gausspr()
Hi there,
I'm trying to do a regression experiment on a multidimensional
dataset where both x and y in the model are multidimensional
vectors.
I'm using R version 2.9.2, updated packages, on a Linux box.
I've tried gausspr(), ksvm() and rvm(), and the models are
computed fine, but I'm always getting the same error message
when I try to use predict():
"Error in