Displaying 20 results from an estimated 20000 matches similar to: "rm.outlier produces a list"
2011 Sep 28
1
removing outliers in non-normal distributions
Hello,
I'm seeking ideas on how to remove outliers from a non-normal distribution
predictor variable. We wish to reset points deemed outliers to a truncated
value that is less extreme. (I've seen many posts requesting outlier removal
systems. It seems like most of the replies center around "why do you want to
remove them", "you shouldn't remove them", "it
2006 Apr 28
1
Error in rm.outlier method
Hi,
I am trying to use rm.outlier method but encountering following error:
> y <- rnorm(100)
> rm.outlier(y)
Error:
Error in if (nrow(x) != ncol(x)) stop("x must be a square matrix") :
argument is of length zero
Whats wrong here?
TIA
Sachin
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2008 May 27
1
label outliers in geom_boxplot (ggplot2)
Dear List and Hadley,
I would like to have a boxplot with ggplot2 and have the outlier values
labelled with their "name" attribute. So I did
> library(ggplot2)
> dat=data.frame(num=rep(1,20), val=c(runif(18),3,3.5),
name=letters[1:20])
> p=ggplot(dat, aes(y=val, x=num))+geom_boxplot(outlier.size=4,
outlier.colour="green")
>
2005 Feb 25
2
outlier threshold
For the analysis of financial data wih a large variance, what is the best way to select an outlier threshold?
Listed below, is there a best method to select an outlier threshold and how does R calculate it?
In R, how do you find the outlier threshold through an interquartile range?
In R, how do you find the outlier threshold using the hist command?
In R, how do you find the outlier threshold
2012 Feb 09
1
Outlier removal techniques
Hello,
I need to analyse a data matrix with dimensions of 30x100.
Before analysing the data there is, however, a need to remove outliers from
the data.
I read quite a lot about outlier removal already and I think the most common
technique for that seems to be Principal Component Analysis (PCA). However,
I think that these technqiue is quite subjective. When is an outlier an
outlier?
I uploaded
2009 Feb 14
2
implementing Grubbs outlier test on a large dataframe
Hi!
I'm trying to implement an outlier test once/row in a large dataframe.
Ideally, I'd do this then add the Pvalue results and the number flagged as
an outlier as two new separate columns to the dataframe. Grubbs outlier
test requires a vector and I'm confused how to make each row of my dataframe
a vector, followed by doing a Grubbs test for each row containing the vector
of numbers
2000 Apr 21
1
outlier detection methods in r?
hi -
if I sample from a normal distribution with something like
n100<-rnorm(100,0,1)
and add an outlier with
n100[10]<-4
then
qqnorm(n100)
visually shows the point 4 as an outlier
and calculating the probablity of a value of 4 or bigger in 100 samples of norm(0,1)
gives
> 1-exp(log(pnorm(4,0,1))*100)
[1] 0.003162164
If I have more than 1 sample above outlier threshold the math is a
2010 Nov 30
3
Outlier statistics question
I have a statistical question.
The data sets I am working with are right-skewed so I have been
plotting the log transformations of my data. I am using a Grubbs Test
to detect outliers in the data, but I get different outcomes depending
on whether I run the test on the original data or the log(data). Here
is one of the problematic sets:
fgf2p50=c(1.563,2.161,2.529,2.726,2.442,5.047)
2004 Jun 30
1
outlier tests
I have been learning about some outlier tests -- Dixon
and Grubb, specifically -- for small data sets. When
I try help.start() and search for outlier tests, the
only response I manage to find is the Bonferroni test
avaiable from the CAR package... are there any other
packages the offer outlier tests? Are the Dixon and
Grubb tests "good" for small samples or are others
more
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))){
2009 Sep 12
1
medcouple-based outlier detection in R
I need to detect outliers in a large data set which is highly right-skewed. I plan to use medcouple-based outlier detection. Is there any support for medcouple-based outlier detection in R? Are there any other routines in R to perform outlier detection in highly right-skewed data?
Manuj Sharma
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2005 Aug 04
1
some thoughts on outlier detection, need help!
Dear listers:
I have an idea to do the outlier detection and I need to use R to
implement it first. Here I hope I can get some input from all the
guru's here.
I select distance-based approach---
step 1:
calculate the distance of any two rows for a dataframe. considering
the scaling among different variables, I choose mahalanobis, using
variance as scaler.
step 2:
Let k be the number of
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 Feb 25
4
Temporal Analysis of variable x; How to select the outlier threshold in R?
For a financial data set with large variance, I'm trying to find the
outlier threshold of one variable "x" over a two year period. I
qqplot(x2001, x2002) and found a normal distribution. The latter part of
the normal distribution did not look linear though. Is there a suitable
method in R to find the outlier threshold of this variable from 2001 and
2002 in R?
2009 Feb 14
6
Outlier Detection for timeseries
Hello R users,
Can someone tell if there is a package in R that can do outlier detection
that give outputs simiilar to what I got from SAS below.
Many thanks in advance for any help!
Outlier Details
Approx
Chi-
2011 Oct 11
1
high and lowest with names
Hello,
I'm looking to get the values, row names and column names of the largest and
smallest values in a matrix.
Example (except is does not include the names):
> x <- swiss$Education[1:25]
> dat = matrix(x,5,5)
> colnames(dat) = c('a','b','c','d','c')
> rownames(dat) = c('z','y','x','w','v')
>
2010 Jul 26
1
Outlier detection in bimodal distribution
Hi,
I was looking for a package that would help with outlier detection for bimodal
distributions. I have tried 'outliers' and 'extremevalues' packages, but am not
sure if they are ok for bimodal distribution.
Any help would be highly appreciated!
thanks,
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2008 Sep 18
1
outlier and whisker in boxplot
Hi, Dear R-users:
Sorry for bothering your guys again. I think I should rewrite my question.
I know how to extend whisker by using range. The question is that I will set
the range=1.5, and at the same time, I only want to show the extreme
outlier, like 0.01% and 99.99% percentile, so what should I do?
Thank you very much!
Catherine
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2011 Apr 09
1
Robust Statistics for Outlier Detection
Hi Dear All,
Can someone give me a suggestion about which robust statistics are most
appropriate for outlier detection in linear models, and is available with R
?
Thanks for any idea.
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2005 Apr 22
2
Hoaglin Outlier Method
I am a new user of R so please bear with me. I have reviewed some R books,
FAQs and such but the volume of material is great. I am in the process of
porting my current SAS and SVS Script code to Lotus Approach, R and
WordPerfect.
My question is, can you help me determine the best R method to implement
the Hoaglin Outlier Method? It is used in the Appendix A and B of the fo
llowing link.