Displaying 20 results from an estimated 10000 matches similar to: "Question about randomForest"
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>
2018 May 31
2
predicciones sobre el OOB de randomForest
Gracias Carlos. No uso caret, pero lo miraré.
Quoting Carlos Ortega <cof en qualityexcellence.es>:
> Hola,
>
> Creo que si utilizas "caret" y en la función "trainControl()" defines "oob"
> como criterio de randomización, puedes luego recuperar del objeto del
> modelo, las predicciones individuales...
>
> Saludos,
> Carlos Ortega
>
2008 Jul 20
1
confusion matrix in randomForest
I have a question on the output generated by randomForest in classification
mode, specifically, the confusion matrix. The confusion matrix lists the
various classes and how the forest classified each one, plus the
classification error. Are these numbers essentially averages over all the
trees in the forest? If so, is there a way I can get the standard deviation
values out of the randomForest,
2003 Aug 20
2
RandomForest
Hello,
When I plot or look at the error rate vector for a random forest
(rf$err.rate) it looks like a descending function except for a few first
points of the vector with error rates values lower(sometimes much lower)
than the general level of error rates for a forest with such number of trees
when the error rates stop descending. Does it mean that there is a tree(s)
(that is built the first in
2009 Apr 10
1
Random Forests: Question about R^2
Dear Random Forests gurus,
I have a question about R^2 provided by randomForest (for regression).
I don't succeed in finding this information.
In the help file for randomForest under "Value" it says:
rsq: (regression only) - "pseudo R-squared'': 1 - mse / Var(y).
Could someone please explain in somewhat more detail how exactly R^2
is calculated?
Is "mse"
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 ).
2003 Sep 16
1
simplifying randomForest(s)
Dear All,
I have been using the randomForest package for a couple of difficult
prediction problems (which also share p >> n). The performance is good, but
since all the variables in the data set are used, interpretation of what is
going on is not easy, even after looking at variable importance as produced
by the randomForest run.
I have tried a simple "variable selection"
2012 Apr 13
1
caret package: custom summary function in trainControl doesn't work with oob?
Hi all,
I've been using a custom summary function to optimise regression model
methods using the caret package. This has worked smoothly. I've been using
the default bootstrapping resampling method. For bagging models
(specifically randomForest in this case) caret can, in theory, uses the
out-of-bag (oob) error estimate from the model instead of resampling, which
(in theory) is largely
2012 May 05
1
No Data in randomForest predict
I would like to ask a general question about the randomForest predict
function and how it handles No Data values. I understand that you can omit
No Data values while developing the randomForest object, but how does it
handle No Data in the prediction phase? I would like the output to be NA
if any (not just all) of the input data have an NA value. It is not clear
to me if this is the default or
2007 Apr 29
1
randomForest gives different results for formula call v. x, y methods. Why?
Just out of curiosity, I took the default "iris" example in the RF
helpfile...
but seeing the admonition against using the formula interface for large data
sets, I wanted to play around a bit to see how the various options affected
the output. Found something interesting I couldn't find documentation for...
Just like the example...
> set.seed(12) # to be sure I have
2010 Apr 25
1
randomForest predictions with new data
Hi
I am new to R, randomForest and I have read about how to use it in your old
mails. I have also run the predictions examples from CRAN. But I still don't
understand how to use it right.
The thing that I don't understand is how to run the result from the
randomForest on one line (post) with newdata to get a good guess. What I
mean is if I put in a new observation of iris how do I
2010 Dec 11
1
randomForest: help with combine() function
I've built two RF objects (RF1 and RF2) and have tried to combine
them, but I get the following error:
Error in rf$votes + ifelse(is.na(rflist[[i]]$votes), 0, rflist[[i]]$votes) :
non-conformable arrays
In addition: Warning message:
In rf$oob.times + rflist[[i]]$oob.times :
longer object length is not a multiple of shorter object length
Both RF models use the same variables, although
2004 Dec 10
1
predict.randomForest
I have a data.frame with a series of variables tagged to a binary
response ('present'/'absent'). I am trying to use randomForest to
predict present/absent in a second dataset. After a lot a fiddling
(using two data frames, making sure data types are the same, lots of
testing with data that works such as data(iris)) I've settled on
combining all my data into one data.frame
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
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
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
2018 May 31
2
predicciones sobre el OOB de randomForest
Muy buenas, ¿sabe alguien cómo obtener las predicciones sobre el out
of bag que hace randomForest?
Manuel
.
--
Dr Manuel Mendoza
Department of Biogeography and Global Change
National Museum of Natural History (MNCN)
Spanish Scientific Council (CSIC)
C/ Serrano 115bis, 28006 MADRID
Spain
2009 Apr 07
1
Concern with randomForest
Hi all,
When running a randomForest run using the following command:
forestplas=randomForest(Prev~.,data=plas,ntree=200000)
print(forestplas)
I get the following result:
Call:
randomForest(formula = Prev ~ ., data = plas, ntree = 2e+05,
importance = TRUE)
Type of random forest: regression
Number of trees: 2e+05
No. of variables tried at each split: 5
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
2003 Apr 02
4
randomForests predict problem
Hello everybody,
I'm testing the randomForest package in order to do some simulations and I
get some trouble with the prediction of new values. The random forest
computation is fine but each time I try to predict values with the newly
created object, I get an error message. I thought I was because NA values
in the dataframe, but I cleaned them and still got the same error. What am
I