Displaying 20 results from an estimated 6000 matches similar to: "Random Forest"
2018 Dec 13
2
Random Forest con poca "n" y muchos predictores
Hola,
Me he iniciado hace poco en Machine Learning, y tengo una duda sobre mis
conjuntos de datos: el primero tiene 37 variables explicativas y 116
instancias, y el segundo, 140 variables explicativas y 195 instancias. El
primero lo veo bien, ya que hay 3 veces más casos que variables
explicativas, pero creo que el segundo caso puede suponer un problema al
haber casi el mismo número de
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 ).
2005 Sep 08
2
Re-evaluating the tree in the random forest
Dear mailinglist members,
I was wondering if there was a way to re-evaluate the
instances of a tree (in the forest) again after I have
manually changed a splitpoint (or split variable) of a
decision node. Here's an illustration:
library("randomForest")
forest.rf <- randomForest(formula = Species ~ ., data
= iris, do.trace = TRUE, ntree = 3, mtry = 2,
norm.votes = FALSE)
# I am
2013 Feb 03
3
RandomForest, Party and Memory Management
Dear All,
For a data mining project, I am relying heavily on the RandomForest and
Party packages.
Due to the large size of the data set, I have often memory problems (in
particular with the Party package; RandomForest seems to use less memory).
I really have two questions at this point
1) Please see how I am using the Party and RandomForest packages. Any
comment is welcome and useful.
2005 Jul 21
4
RandomForest question
Hello,
I'm trying to find out the optimal number of splits (mtry parameter) for a randomForest classification. The classification is binary and there are 32 explanatory variables (mostly factors with each up to 4 levels but also some numeric variables) and 575 cases.
I've seen that although there are only 32 explanatory variables the best classification performance is reached when
2011 Nov 17
1
tuning random forest. An unexpected result
Dear Researches,
I am using RF (in regression way) for analize several metrics extract from
image. I am tuning RF setting a loop using different range of mtry, tree
and nodesize using the lower value of MSE-OOB
mtry from 1 to 5
nodesize from1 to 10
tree from 1 to 500
using this paper as refery
Palmer, D. S., O'Boyle, N. M., Glen, R. C., & Mitchell, J. B. O. (2007).
Random Forest Models
2013 Mar 24
1
Random Forest, Giving More Importance to Some Data
Dear All,
I am using randomForest to predict the final selling price of some items.
As it often happens, I have a lot of (noisy) historical data, but the
question is not so much about data cleaning.
The dataset for which I need to carry out some predictions are fairly
recent sales or even some sales that will took place in the near future.
As a consequence, historical data should be somehow
2007 Jan 07
2
creating a list of lists
Hello,
I'm trying to create a series of randomForest objects, basically in a
loop like this:
forests <- list();
for (level in 1:10) {
# do some other things here
# create a random forest
forest <- randomForest(
x = x.level,
y = z.level,
ntree = trees
);
forests <- c(forests, forest);
}
But instead of creating a list of 10 forests, this creates a list
2003 Apr 12
5
rpart vs. randomForest
Greetings. I'm trying to determine whether to use rpart or randomForest
for a classification tree. Has anybody tested efficacy formally? I've
run both and the confusion matrix for rf beats rpart. I've looking at
the rf help page and am unable to figure out how to extract the tree.
But more than that I'm looking for a more comprehensive user's guide
for randomForest including
2004 Oct 13
1
random forest -optimising mtry
Dear R-helpers,
I'm working on mass spectra in randomForest/R, and following the
recommendations for the case of noisy variables, I don't want to use the
default mtry (sqrt of nvariables), but I'm not sure up to which
proportion mtry/nvariables it makes sense to increase mtry without
"overtuning" RF.
Let me tell my example: I have 106 spectra belonging to 4 classes, the
2008 Dec 26
2
about randomForest
hello,
I want to use randomForest to classify a matrix which is 331030?42,the last column is class signal.I use ?
Memebers.rf<-randomForest(class~.,data=Memebers,proximity=TRUE,mtry=6,ntree=200) which told me" the error is matrix(0,n,n) set too elements"
then I use:
Memebers.rf<-randomForest(class~.,data=Memebers,importance=TRUE,proximity=TRUE) which told me"the error is
2005 Mar 22
2
Error: Can not handle categorical predictors with more than 32 categories.
Hi All,
My question is in regards to an error generated when using randomForest
in R. Is there a special way to format the data in order to avoid this
error, or am I completely confused on what the error implies?
"Error in randomForest.default(m, y, ...) :
Can not handle categorical predictors with more than 32 categories."
This is generated from the command line:
>
2013 Jan 15
1
Random Forest Error for Factor to Character column
Hi,
Can someone please offer me some guidance?
I imported some data. One of the columns called "JOBTITLE" when imported was imported as a factor column with 416 levels.
I subset the data in such a way that only 4 levels have data in "JOBTITLE" and tried running randomForest but it complained about "JOBTITLE" having more than 32 categories. I know that is the limit
2010 May 25
1
Need Help! Poor performance about randomForest for large data
Hi, dears,
I am processing some data with 60 columns, and 286,730 rows.
Most columns are numerical value, and some columns are categorical value.
It turns out that: when ntree sets to the default value (500), it says "can
not allocate a vector of 1.1 GB size"; And when I set ntree to be a very
small number like 10, it will run for hours.
I use the (x,y) rather than the (formula,data).
2009 Aug 13
2
randomForest question--problem with ntree
Hi,
I would like to use a random Forest model to get an idea about which variables from a dataset may have some prognostic significance in a smallish study. The default for the number of trees seems to be 500. I tried changing the default to ntree=2000 or ntree=200 and the results appear identical. Have changed mtry from mtry=5 to mtry=6 successfully. Have seen same problem on both a Windows
2010 Oct 22
2
Random Forest AUC
Guys,
I used Random Forest with a couple of data sets I had to predict for binary
response. In all the cases, the AUC of the training set is coming to be 1.
Is this always the case with random forests? Can someone please clarify
this?
I have given a simple example, first using logistic regression and then
using random forests to explain the problem. AUC of the random forest is
coming out to be
2010 Jul 14
1
randomForest outlier return NA
Dear R-users,
I have a problem with randomForest{outlier}.
After running the following code ( that produces a silly data set and builds
a model with randomForest ):
#######################
library(randomForest)
set.seed(0)
## build data set
X <- rbind( matrix( runif(n=400,min=-1,max=1), ncol = 10 ) ,
rep(1,times= 10 ) )
Y <- matrix( nrow = nrow(X), ncol = 1)
for( i in (1:nrow(X))){
2018 Jan 20
2
Random Forests
Si, Carlos. Yo hago lo mismo, pero esos mismos numeritos salen enormes.
> treesize(RFfit)
[1] 4304 4302 4311 4319 4343 4298 4298 4311 4349 4327 4331 4317
4294 4321 4283 4362
[17] 4300 4330 4266 4331 4308 4352 4294 4315 4372 4349 4331 4347
4329 4348 4298 4335
[33] 4346 4396 4345 4313 4293 4276 4353 4272 4304 4325 4317 4336
4308 4351 4374 4324
[49] 4386 4359 4311 4346 4300
2002 Jun 12
3
help debugging segfaults
(Sorry for the cross-post--- I wasn't sure which list is more
appropriate...)
Hi everyone,
I've run into segfaults when using my randomForest package on large dataset
(e.g., 100 x 15200) and large number of trees (e.g., ntree=7000 and
mtry=3000). I'm wondering if anyone can give me some hints on where to look
for the problem.
The randomForest package mainly consists of two things:
2002 Jun 12
3
help debugging segfaults
(Sorry for the cross-post--- I wasn't sure which list is more
appropriate...)
Hi everyone,
I've run into segfaults when using my randomForest package on large dataset
(e.g., 100 x 15200) and large number of trees (e.g., ntree=7000 and
mtry=3000). I'm wondering if anyone can give me some hints on where to look
for the problem.
The randomForest package mainly consists of two things: