Displaying 20 results from an estimated 2000 matches similar to: "What is the default nPerm for regression in randomForest?"
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 ).
2010 May 05
1
randomForest: predictor importance (for regressions)
I have a question about predictor importances in randomForest.
Once I've run randomForest and got my object, I get their importances:
rfresult$importance
I also get the "standard errors" of the permutation-based importance
measure: rfresult$importanceSD
I have 2 questions:
1. Because I am dealing with regressions, I am getting an importance object
(rfresult$importance) with two
2004 Jan 20
1
random forest question
Hi,
here are three results of random forest (version 4.0-1).
The results seem to be more or less the same which is strange because I
changed the classwt.
I hoped that for example classwt=c(0.45,0.1,0.45) would result in fewer
cases classified as class 2. Did I understand something wrong?
Christian
x1rf <- randomForest(x=as.data.frame(mfilters[cvtrain,]),
2010 Oct 01
3
Suppressing printing in the function
Hello!
I wrote a function that returns a data frame. Nowhere in the function
do I say print(my.data.frame), but when I run the function - the data
frame is printed on the console.
Is there any way to suppress it?
Thank you!
--
Dimitri Liakhovitski
Ninah Consulting
www.ninah.com
2011 Feb 25
6
preventing repeat in "paste"
Hello!
s<-"start"; e<-"end"
middle<-as.character(c(1,2,3))
I would like to get the following result:
"start 123 end" or "start 1 2 3 end" or "start 1,2,3 end"
How can I avoide this (undesired) result:
paste(s,middle,e,sep=" ")
Thank you!
--
Dimitri Liakhovitski
Ninah Consulting
www.ninah.com
2009 Oct 13
4
replacing period with a space
Dear R-ers!
I have x as a variable in a data frame x.
x<-data.frame(x=c("aa.bb","cc.dd.ee"))
x$x<-as.character(x$x)
x
I am sorry for such a simple question - but how can I replace all
periods in x$x with spaces?
sub('.', ' ', x$x) - removes all letters to the left of each period...
Thanks a lot for your advice!
--
Dimitri Liakhovitski
Ninah.com
2010 Oct 25
3
finding the year of a date
I know that I can use as.yearmon in the package "zoo" to find the year
and the month of a date.
I can use as. yearqtr to find the year and the quarter.
But how can one find just the year of a date?
Thanks a lot!
--
Dimitri Liakhovitski
Ninah Consulting
www.ninah.com
2009 Sep 23
2
Function to check if a vector contains a given value?
Dear R'rs,
is there a function that checks if a given vector contains a certain value.
E.g., x<-c(1,2,3,4).
How can I get a TRUE or FALSE for whether x contains a 2?
--
Dimitri Liakhovitski
Ninah.com
Dimitri.Liakhovitski at ninah.com
2010 Aug 13
3
transforming dates into years
Hello!
If I have in my data frame MyFrame a variable saved as a Date and want
to translate it into years, I currently do it like this using "zoo":
library(zoo)
as.year <- function(x) as.numeric(floor(as.yearmon(x)))
myFrame$year<-as.year(myFrame$date)
Is there a function that would do it directly - like "as.yearmon" -
but for years?
Thank you!
--
Dimitri
2010 Mar 04
4
Analogue to SPSS regression commands ENTER and REMOVE in R?
I am not sure if this question has been asked before - but is there a
procedure in R (in lm or glm?) that is equivalent to ENTER and REMOVE
regression commands in SPSS?
Thanks a lot!
--
Dimitri Liakhovitski
Ninah.com
Dimitri.Liakhovitski at ninah.com
2010 Mar 18
1
R takes long time to open
Hello.
Until today I've been using R2.9 and since today R2.10 (on a PC).
In both of them it takes about 20 sec for the prompt to appear IN R
console after I start R. And every time it says: "Previous saved work
space restored" - even if I have not saved any workspace or, in case
of R2.10 - even though I have not used it once.
In the older versions - R would start within 2-3 sec.
Is
2010 May 08
1
Increasing the font size on axes in trellis
Hello,
the code below gives me the picture I need - but there is on small
thing I can't figure out.
The plot has very small tick mark labels for both axes. I don't mean
the axis labels - they are both good, but what is shown near the tick
marks.
Please help me figure out what parameter I should add to make those
larger. I tried sticking cex.lab=1.3 in different places but it didn't
2011 Feb 24
4
Running code sequentially from separate scripts (but not functions)
Hello!
I am wondering if it's possible to run - in sequence - code that is
stored in several R scripts.
For example:
Script in the file "code1.r" contains the code:
a = 3; b = 5; c = a + b
Script in the file "code2.r" contains the code:
d = 10; e = d - c
Script in the file "code3.r" contains the code:
result=e/a
I understand that I could write those 3 scripts
2010 Mar 09
2
looping through predictors
Dear R-ers,
I have a data frame data with predictors x1 through x5 and the
response variable y.
I am running a simple regression:
reg<-lm(y~x1, data=data)
I would like to loop through all predictors. Something like:
predictors<-c("x1","x2",... "x10)
for(i in predictors){
reg<-lm(y~i)
etc.
}
But it's not working. I am getting an error:
Error in
2010 Aug 04
6
applying strsplit to a whole column
I am sorry, I'd like to split my column ("names") such that all the
beginning of a string ("X..") is gone and only the rest of the text is
left.
x<-data.frame(names=c("X..aba","X..abb","X..abc","X..abd"))
x$names<-as.character(x$names)
(x)
str(x)
Can't figure out how to apply strsplit in this situation - without
using a
2011 Feb 03
1
rgenoud for multiple chips: does a more recent special version of "snow" exist?
Dear everyone,
I am trying to run rgenoud on several chips simultaneusly. I used the
instructions provided on Jasjeet Sekhon's Homepage
(http://sekhon.berkeley.edu/rgenoud/multiple_cpus.html).
However, I have the newer version of R (R 2.12) installed - for a
64-bit machine. So, when I tried to install the special version of
"snow" from a zip file provided by Jasjeet on his page, R
2010 Oct 29
1
help pages do not open
I have just installed R 12.
I have Windows 7, 64-bit verison.
I currently have IE as my default browser. The internet connection is very good.
Whenever I try to run a help command (?lm, for example), I get this error:
Error in shell.exec(url) : access to
'http://127.0.0.1:20271/library/stats/html/lm.html' denied
I first got this message when Google Chrome was my default browser.
For some
2010 Nov 03
2
biding rows while merging at the same time
Hello!
I have 2 data frames like this (well, actually, I have 200 of them):
df1<-data.frame(location=c("loc 1","loc 2","loc
3"),date=c("1/1/2010","1/1/2010","1/1/2010"), a=1:3,b=11:13,c=111:113)
df2<-data.frame(location=c("loc 1","loc 2","loc
2009 Sep 17
2
referring to a row number and to a row condition, and to columns simultaneously
Hello, dear R-ers!
I have a data frame:
x<-data.frame(a=c(4,2,4,1,3,4),b=c(1,3,4,1,5,0),c=c(NA,2,5,3,4,NA),d=rep(NA,6),e=rep(NA,6))
x
When x$a==1, I would like to replace NAs in columns d and e with 8 and
9, respectively
When x$a != 1, I would like to replace NAs in columns d and e 101 and
1022, respectively.
However, I only want to do it for rows 2:5 - while ignoring what's
happening in
2011 May 23
1
weird problem - R is not finding the data for the factor level present in the data
Sorry for no code - but it's a more of a general question.
I have read in a data frame ("|"-delimited, .txt).
daily<-read.table(file="filename.txt",sep="|",header=T)
One of the variables is a factor with 110 levels:
>str(daily$dma_id)
Factor w/ 110 levels "500","501","503",...
108 levels of this factor happen to be numbers