Displaying 20 results from an estimated 1000 matches similar to: "random forest"
2008 Jun 15
1
randomForest, 'No forest component...' error while calling Predict()
Dear R-users,
While making a prediction using the randomForest function (package
randomForest) I'm getting the following error message:
"Error in predict.randomForest(model, newdata = CV) : No forest component
in the object"
Here's my complete code. For reproducing this task, please find my 2 data
sets attached ( http://www.nabble.com/file/p17855119/data.rar data.rar ).
2012 Mar 08
2
Regarding randomForest regression
Sir,
This query is related to randomForest regression using R.
I have a dataset called qsar.arff which I use as my training set and
then I run the following function -
rf=randomForest(x=train,y=trainy,xtest=train,ytest=trainy,ntree=500)
where train is a matrix of predictors without the column to be
predicted(the target column), trainy is the target column.I feed the same
data
2009 Dec 10
2
different randomForest performance for same data
Hello,
I came across a problem when building a randomForest model. Maybe someone can help me.
I have a training- and a testdataset with a discrete response and ten predictors (numeric and factor variables). The two datasets are similar in terms of number of predictor, name of variables and datatype of variables (factor, numeric) except that only one predictor has got 20 levels in the training
2004 Jan 20
1
random forest question
Hi,
here are three results of random forest (version 4.0-1).
The results seem to be more or less the same which is strange because I
changed the classwt.
I hoped that for example classwt=c(0.45,0.1,0.45) would result in fewer
cases classified as class 2. Did I understand something wrong?
Christian
x1rf <- randomForest(x=as.data.frame(mfilters[cvtrain,]),
2004 Apr 15
7
all(logical(0)) and any(logical(0))
Dear R-help,
I was bitten by the behavior of all() when given logical(0): It is TRUE!
(And any(logical(0)) is FALSE.) Wouldn't it be better to return logical(0)
in both cases?
The problem surfaced because some un-named individual called randomForest(x,
y, xtest, ytest,...), and gave y as a two-level factor, but ytest as just
numeric vector. I thought I check for that in my code by testing
2009 Apr 04
1
error in trmesh (alphahull package)
Hello R community,
I have cross-posted with r-sig-geo as this issue could fall under either
interest group I believe.
I just came accross the alphahull package and am very pleased I may not
need to use CGAL anymore for this purpose. However, I am having a
problem computing alpha shapes with my point data, and it seems to have
to do with the spatial configuration of my points (which form
2003 Nov 25
2
RandomForest & memory demand
Hi,
is it correct that i need ~ 2GB RAM that it's
possible to work with the default setting
ntree=500 and a data.frame with 100.000 rows
and max. 10 columns for training and testing?
P.S.
It's possible calculate approximate the
memory demand for different settings with RF?
Many thanks & regards,
Christian
2012 Dec 03
2
Different results from random.Forest with test option and using predict function
Hello R Gurus,
I am perplexed by the different results I obtained when I ran code like
this:
set.seed(100)
test1<-randomForest(BinaryY~., data=Xvars, trees=51, mtry=5, seed=200)
predict(test1, newdata=cbind(NewBinaryY, NewXs), type="response")
and this code:
set.seed(100)
test2<-randomForest(BinaryY~., data=Xvars, trees=51, mtry=5, seed=200,
xtest=NewXs, ytest=NewBinarY)
The
2011 Nov 09
2
Error in drawing
I have got following error in drawing wavelet fitting. can some one help?
> library(faraway)
> data(lidar)
> newlidar<-lidar[c(1:128),]
> library(wavethresh)
> wds <- wd(newlidar$logratio)
> draw(wds)
Error in plot.default(x = x, y = zwr, main = main, sub = sub, xlab = xlab,
:
formal argument "type" matched by multiple actual arguments
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2005 Oct 11
1
a problem in random forest
Hi, there:
I spent some time on this but I think I really cannot figure it out, maybe I
missed something here:
my data looks like this:
> dim(trn3)
[1] 7361 209
> dim(val3)
[1] 7427 209
> mg.rf2<-randomForest(x=trn3[,1:208], y=trn3[,209], data=trn3, xtest=val3[,
1:208], ytest=val3[,209], importance=T)
my test data has 7427 observations but after prediction,
> dim(mg.rf2$votes)
2009 Sep 15
1
Boost in R
Hello,
does any one know how to interpret this output in R?
> Classification with logitboost
> fit <- logitboost(xlearn, ylearn, xtest, presel=50, mfinal=20)
> summarize(fit, ytest)
Minimal mcr: 0 achieved after 6 boosting step(s)
Fixed mcr: 0 achieved after 20 boosting step(s)
What is "mcr" mean?
Thanks
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2011 Nov 29
3
Problem in log
Hi all I have a function of log defined by y = log(1- exp(-a)), when
exp(-a) is greater, 1, it produce NaN. How can I remove this in R?
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2012 Dec 05
4
Import multiple data frames and combine them using "cbind"
Hi group,
I imported 16 data frames using the function "list.files"
temp <- list.files(path="...........")
myfiles = lapply(temp, read.table,sep = "")
Now I have 16 data set imported in R window.
I want to combine them by row and tried some thing like (Here I am
considering only 20 columns)
for(i in 1:16){
data<- cbind(myfiles[[i]][,1:20])
}
but it
2011 Nov 07
3
Correction in error
Hello R community, following is my code and it shows error, can some one
fix this error and explain why this occurs?
gibbs <-function(m,n, theta = 0, lambda = 1){
alpha <- 1.5
beta <- 1.5
gamma <- 1.5
x<- array(0,c(m+1, 3))
x[1,1] <- theta
x[1,2] <- lambda
x[1,3]<- n
for(t in 2:m+1){
x[t,1] <- rbinom(x[t-1,3], 1, x[t-1,1])
2012 Apr 06
2
Bayesian 95% Credible interval
Hi all,
I have the data from the posterior distribution for some parameter. I want
to find the 95% credible interval. I think "t.test(data)" is only for the
confidence interval. I did not fine function for the Bayesian credible
interval. Could some one suggest me?
Thanks
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2002 Oct 04
1
items in Rd file
Dear R-devel,
I'm encountering a strange problem in a Rd file that I'm working on. In the
"Value" section, I have something like:
=====================
\value{
An object of class \code{randomForest}, which is a list with the
following components:
\item{call}{the original call to \code{randomForest}}
...
For classification problem, the following are also included:
2006 Jul 24
2
RandomForest vs. bayes & svm classification performance
Hi
This is a question regarding classification performance using different methods.
So far I've tried NaiveBayes (klaR package), svm (e1071) package and
randomForest (randomForest). What has puzzled me is that randomForest seems to
perform far better (32% classification error) than svm and NaiveBayes, which
have similar classification errors (45%, 48% respectively). A similar
difference in
2011 Nov 18
3
Permutations
Hi all,
why factorial(150) shows the error out of range in 'gammafn'?
I have to calculate the number of subset formed by 150 samples taking 10 at
a time. How is this possible?
best
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2011 Nov 16
2
Error in random walk Metroplis-hasting
Hi R community,
I have some data set and construct the likelihood as follows
likelihood <- function(alpha,beta){
lh<-1
d<-0
p<-0
k<-NULL
data<-read.table("epidemic.txt",header = TRUE)
attach(data, warn.conflicts = F)
k <-which(inftime==1)
d <- (sqrt((x-x[k])^2+(y-y[k])^2))^(-beta)
p<-1 - exp(-alpha*d)
for(i in 1:100){
2010 May 05
1
What is the default nPerm for regression in randomForest?
Could not find it in ?randomForest.
Thank you for your help!
--
Dimitri Liakhovitski
Ninah.com
Dimitri.Liakhovitski at ninah.com