Displaying 20 results from an estimated 400 matches similar to: "randomForest help"
2011 Jan 03
1
randomForest speed improvements
Hi there,
We're trying to use randomForest to do some predictions. The test-harness
for our code is pretty straightforward:
library ('randomForest');
data202 <- read.csv ("random.csv", header=TRUE);
x<- data202[1:50000,1:6];
y<- data202[1:50000,8];
y<- y[,drop=TRUE];
x2 <- data202[50001:60000,1:6];
y2 <- data202[50001:60000,8];
y2 <-
2008 Jun 18
2
randomForest outlier
I try to use ?randomForest to find variables that are the most important to
divide my dataset (continuous, categorical variables) in two given groups.
But when I plot the outliers:
plot(outlier(FemMalSex_NAavoid88.rf33, cls=FemMalSex_NAavoid88$Sex),
type="h",col=c("red","green")[as.numeric(FemMalSex_NAavoid88$Sex)])
it seems to me that all my values appear as
2005 Oct 25
0
Examples of "classwt", "strata", and "sampsize" in randomForest?
Just browsing the documentation, and searching the list came up short... I
have some unbalance data and was wondering if, in a "0" v "1" classification
forest, if these options might yield better predictions when the proportion
of one class is low (less than 10% in a sample of 2,000 observations).
Not sure how to specify these terms... from the docs, we have:
classwt: Priors
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
2013 Feb 11
0
getTree visualization (randomForest)
Hi,
I would like to visualize a tree extracted from a random forest using
getTree {randomForest}.
I'm wondering if there is any way to do it directly or to convert my tree
to any other class of tree repesentation, which then can be plotted?
Regards,
Umang Rathi
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2003 Aug 26
1
rfImpute (for randomForest) crashed
In trying to execute this line in R (Version 1.7.1 (2003-06-16), under
windows XP pro), with the randomForest library (about two weeks old) loaded,
the program crashed:
bost4rf <- rfImpute(TargetDensity~.,data=bost4rf0)
Specifically, an XP dialog box popped up, saying ?R for windows GUI
front-end has encountered a problem and needs to close.? That was the
dialog saying asking whether I
2007 Jun 06
0
Question on RandomForest in unsupervised mode
Hi,
I attempted to run the randomForest() function on a dataset without
predefined classes. According to the manual, running randomForest
without a response variable/class labels should result in the
function assuming you are running in unsupervised mode. In this case,
I understand that my data is all assigned to one class whereas a
second synthetic class is made up, which is assigned
2005 Jan 17
0
randomForest: too many element specified?
> From: luk
>
> When I run randonForest with a 169453x5 matrix, I got the
> following message.
>
> Error in matrix(0, n, n) : matrix: too many elements specified
>
> Can you please advise me how to solve this problem?
>
> Thanks,
>
> Lu
1. When asking new questions, please don't reply to other posts.
2. When asking questions like these, please
2011 Apr 07
0
understanding randomForest results
How do I read/interpret the output of varImpPlot() for a randomForest
object?
Regards,
Divya
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2005 Jan 06
1
leave-one-out cross validation for randomForest
Dear all,
Can I get the leave-one-out cross validation error of randomForest in
R? I only found tune(), which got the 10-fold cross validation error.
Thanks for any information.
Xin LIU
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2004 Oct 18
1
R crashes while running RandomForest
I tried to use RF build a model with a continuous variable as the
dependent. However, whenever I ran it, R just crashed.
But when I catigorize the dependent variable as a binary variable and
ran the same model again. It just works.
Is there anyone who can help me out? I really appreciate it.
2005 Oct 03
1
seeking an simple example of randomForest package - thanks!
hi, dear all,
does anyboby have an simple example of
classification by using randomForest? Thanks a lot!
best
assicma
2007 Sep 14
1
generate ROC curve using randomForest package
Hi,
I am new here. I would like to compare the performance of the random forest
model with support vector machine. Can anybody let me know how to generate
a ROC curve for random forest model since there is no need to run the
cross-validation. Thank you very much!
TL
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2013 Sep 30
1
Split type in the RandomForest package
Hi guys,
I'm new to Random Forest package and I'd like to know what type of split is used in the package for classification? Or can I configure the package to use different split type (like simple split alongside single attribute axis or linear split based on several attributes etc..)
Thanks a lot!
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2009 Jan 10
0
Rserve/RandomForest does not work with a CSV?
Hi all,
We're using Rserve and RandomForest to do classification from within a
Java program. The total is about 4 lines of R code:
library('randomForest')
x
y
future
fit<-randomForest(x,y,no.action=na.roughfix,importance=T,proximity=T)
p<-predict(fit, future)
What is very frustrating is that we have tried this two different ways
(both work in R):
1. Load x, y, and future
2008 Oct 08
0
[randomForest]: display decision trees
Hi,
I'm using the package randomForest to generate a classifier for the exemplary
iris data set:
data(iris)
iris.rf<-randomForest(Species~.,iris)
Is it possible to print all decision trees in the generated forest?
If so, can the trees be also written to disk?
What I actually need is to translate the decision trees in a random forest
into equivalent C++ if-then-else constructs to
2006 Jan 27
1
save trained randomForest model
I used the following command to train a randomForest model
train.rf <- randomForest(grp ~ ., data=tr, ntree=100, mtry=50)
My question is how to save the trained model so that it can be loaded later for testing new samples?
Thanks,
Luk
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2004 Apr 23
1
Extracting the MSE and % Variance from RandomForest
Several ways:
1. Read ?randomForest, especially the `Value' section.
2. Look at str(myforest.rf).
3. Look at print.randomForest.
If the forest has 100 trees, then the mse and rsq are vectors with 100
elements each, the i-th element being the mse (or rsq) of the forest
consisting of the first i trees. So the last element is the mse (or rsq) of
the whole forest.
HTH,
Andy
> From: David
2006 Mar 08
1
Unsupervised RandomForest
Dear all,
I am trying to calculate the proximity matrix for a data set with 16 variables
and 6804 observations using random forests. I have a Pentium 4, 3.00GHz
processor with 1 GB of RAM. When I use the command
randomForest(data.scale,proximity=T)
I get the warning message
Error: cannot allocate vector of size 361675 kb
Is this because I have reached the limit of what my computer is
2008 May 21
1
How to use classwt parameter option in RandomForest
Hi,
I am trying to model a dataset with the response variable Y, which has
6 levels { Great, Greater, Greatest, Weak, Weaker, Weakest}, and
predictor variables X, with continuous and factor variables using
random forests in R. The variable Y acts like an ordinal variable, but
I recoded it as factor variable.
I ran a simulation and got OOB estimate of error rate 60%. I validated
against some