Displaying 20 results from an estimated 10000 matches similar to: "scale subset of data"
2009 Aug 12
5
Nominal variables in SVM?
Hi,
The answers to my previous question about nominal variables has lead me
to a more important question.
What is the "best practice" way to feed nominal variable to an SVM.
For example:
color = ("red, "blue", "green")
I could translate that into an index so I wind up with
color= (1,2,3)
But my concern is that the SVM will now think that the values are
2009 Jul 31
1
scale subsets of grouped data in data frame
Hello,
I'm trying to duplicate what's an easy process in RapidMiner.
In RM, we can simply use two operators:
subgroup iteration
attribute value selection (Can use a regex for the attrribute name.)
I can do this in R with a lot of code and manual steps. It would be
really nice to find a more automated way.
My data looks like this
group group_height group_weight height
2009 Aug 30
1
SVM coefficients
Hello,
I'm using the svm function from the e1071 package.
It works well and gives me nice results.
I'm very curious to see the actual coefficients calculated for each
input variable. (Other packages, like RapidMiner, show you this
automatically.)
I've tried looking at attributes for the model and do see a
"coefficients" item, but printing it returns an NULL result.
2011 Jan 07
2
Stepwise SVM Variable selection
I have a data set with about 30,000 training cases and 103 variable.
I've trained an SVM (using the e1071 package) for a binary classifier
{0,1}. The accuracy isn't great.
I used a grid search over the C and G parameters with an RBF kernel to
find the best settings.
I remember that for least squares, R has a nice stepwise function that
will try combining subsets of variables to find
2011 Sep 05
2
Need more information about VGLM
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2010 May 05
3
Symbolic eigenvalues and eigenvectors
Let's say I had a matrix like this:
library(Ryacas)
x<-Sym("x")
m<-matrix(c(cos (x), sin(x), -sin(x), cos(x)), ncol=2)
How can I use R to obtain the eigenvalues and eigenvectors?
Thanks,
John
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2011 Sep 12
1
Open a file to APPEND
Hi,
I want to store the output of my program to a file. However, With subsequent runs of my code, I'd like to append to the same log file.
Currently, I'm using:
outfile <- file("log.txt", open="w")
cat(results, file=outfile)
This works, but will overwrite the log file each time.
Is there a way to open a file and have R append to the end?
Thanks!
--
Noah
2013 Mar 14
1
Elasticnet - Cross validation problem
Hello,
I am attempting to use elasticnet to classify a number of documents.
The features are words. The data is coded into a matrix with each document as a row and each word as a column. The data is binary, with {0,1} indicating the presence of a word.
I want to use the cross validation function of elasticnet (cv.enet). However, when the code selects a random subset of the data for a given
2011 Mar 24
2
Using C code in R
Hi,
I am new to R and I want to know how to use C code which contains two
functions one called inside another.I know that how to use C code in R if it
has only one function but dont know how to do it in above case. I want to
use the same in R .My C code is as follows.
//#include <R.h>
void sayHello();
void g();
void sayhello() {
Rprintf("Hello world %d\n",global);
}
void
2010 Jun 17
3
Factoring a variable
Hi,
I have a dataset where the results are coded ("yes", "no") We want to
do some machine learning with SVM to predict the "yes" outcome
My problem is that if I just use the as.factor function to convert, then
it reverses the levels.
----------------------
x <- c("no", "no", "no", "yes", "yes", "no",
2009 Aug 03
2
Scale set of 0 values returns NAN??
Hi,
More questions in my ongoing quest to convert from RapidMiner to R.
One thing has become VERY CLEAR: None of the issues I'm asking about
here are addressed in RapidMiner. How it handles misisng values,
scaling, etc. is hidden within the "black box". Using R is forcing me
to take a much deeper look at my data and how my experiments are
constructed. (That's a very
2009 Aug 19
1
Erros with RVM and LSSVM from kernlab library
Hello,
In my ongoing quest to develop a "best" model, I'm testing various forms
of SVM to see which is best for my application.
I have been using the SVM from the e1071 library without problem for
several weeks.
Now, I'm interested in RVM and LSSVM to see if I get better performance.
When running RVM or LSSVM on the exact same data as the SVM{e1071}, I
get an error that I
2009 Jul 27
1
Forumla format?
Hi,
Quick question.
I'm working on training an SVM.
I have a dataframe with about 50 columns. I want to train on 46 of them.
Is there a way to say "All except columns 22,23,25 and 31"?
It would be nice to not have to do +c1 +c2 +c3 +c4, etc for all 48 columns.
Thanks!
-N
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2009 Aug 05
1
Question with apply function
In my continuing quest to generate some summary data, I've come across
some useful suggestions in pasts posts.
The apply operation returns an error, and I can't figure out why.
Can someone help me fix this?
testlogdata <- cbind(testlogdata, range_group=cut(testlogdata$lrm_score,
breaks=c(.9, .8, .7, .6, .5, .4, .3, .2, .1)))
apply(testlogdata, 2, function(x){tapply(x,
2012 Oct 10
2
history() does not work?
Hi,
> history()
gives Error in savehistory(file) : no history available to save
although I can scroll throu history with C^uparrow an C^downarrow.
How can I make history() work and/or show the current history in a file,
so that I can choose from previous commands?
The web did not throw up anything useful.
TIA --Christian
--
Christian W. Hoffmann,
CH - 8915 Hausen am Albis,
2010 Jan 21
2
How to open .rda file in R
Hi,
I have a file containing gene expressions written using the tillingArray package. I used load() and attach() to get the data into R. Both of them works fine. Now I want to see the contents of the file. How can I see the contents of the file?
Thankyou for your time.
Regards,
Ambuj
The INTERNET now has a personality. YOURS! See your Yahoo! Homepage.
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2010 Jun 14
2
Multiple regressions
Hi,
Could you please tell me whether SVM can do multiple regression or not?
Cheers,
Amy
_________________________________________________________________
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2010 Sep 23
2
hdf-files
Dear All,
I have data in HDF file format and would like to read it into R.
I have tried the package hdf5 without success.
Any ideas and suggestions??
Kind regards,
Katrin
--
Katrin Fleischer
Vrije Universiteit Amsterdam
Faculty of Earth and Life Sciences
Subdepartment Hydrolgy and Geo-Environmental Sciences
Room E-360
De Boelelaan 1085
1081 HV AMSTERDAM
Tel: +31 20 59 87391
2012 Feb 20
2
R
Hello, just a couple of short questions that would be much appreciated.
Is there a way of putting a vectors inputs in size order from low to high?
And if I had a random list or TRUE and FALSE, is there a way of finding the 100th TRUE?
Thank you very much,
Elliot Welch
elliot.welch at virgin.net
Sent from my BlackBerry? smartphone
2012 Feb 13
4
Reading in csv with footer
Hi,
I have a CSV file that is formatted well, except that the last line is a "summary" not is CSV format.
Toy example:
label_1, label_2, label_3
1,2,3
3,2,4
2,3,4
Total Rows: 3
When I try to import this into R with: d <- read.table("foo.csv", header=T, sep=",")
It fails to import properly because of the last line.
Currently, I have a shell script that strips