Displaying 20 results from an estimated 3000 matches similar to: "How to identify and exclude the outliers with R?"
2010 Sep 15
1
cochran-grubbs tests results
Hello,
I'm new in this R world and I don't know much about statistics, but now I
have to analize some data and I've got some first queries yet:
I have 5 sets of area mesures and each set has 5 repetitions.
My first step is to check data looking for outliers. I've used the outliers
package. I have to use the cochran test and the grubbs test in case I find
any outlier. The problem
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
2007 Jun 19
5
outlying
hello,
are there functions to detecte outlying observations in samples?
thanks.
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2007 Apr 06
2
How to set the scale of axis?
Hello,everyone.
I want to know how to control the scale of axises.
For example, the range of x axis is (1,100),and I want to show the scale in
the axis as this:
1 20 40 60 80 100.
Is there any parameters in plot() or other functions to set the scale?
Thands!
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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)
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
2011 Dec 30
3
good method of removing outliers?
Happy holidays all!
I know it's very subjective to determine whether some data is outlier or
not...
But are there reasonally good and realistic methods of identifying outliers
in R?
Thanks a lot!
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2005 Apr 14
2
grubbs.test
Dear All,
I have small samples of data (between 6 and 15) for
numerious time series points. I am assuming the data
for each time point is normally distributed. The
problem is that the data arrvies sporadically and I
would like to detect the number of outliers after I
have six data points for any time period. Essentially,
I would like to detect the number of outliers when I
have 6 data points then
2007 Mar 28
3
multi-level modeling & R?
A colleague was asking me if R does multi-level
modelling as opposed to multiple regression. Since I
have no knowledge of multi-level modelling (except 5
minutes googling ) I thought that I would as here.
Does are offer any multi-level modeling packages? It
looked like arm might be one but I was not sure.
Thanks
2013 May 17
0
Using grubbs test for residuals to find outliers
Hi,
I am a new user of R.
This is a conceptual doubt regarding screeing out outliers from the dataset
in regression.
I read up that Cook's distance can be used and if we want to remove
influential observations, we can use the metric (>4/n) (n=no of
observations) to remove any outliers.
I also came across Grubb's test to identify outliers in univariate distns.
(assumed normal) but i
2007 Nov 05
1
Help with cochran.test
Hi,
I have been trying to use the function cochran.test from the Outliers
package to test for homogeneity of variance. This works well except when
I use transformed data. Would anyone have an idea why it doesn't work
and how I could do the cochran test on transformed data?
Thanks,
Stephanie
>library(outliers)
> set.seed(1234)
> x=rnorm(100)
>
2008 Aug 12
3
dixon test
Hi, I need some help using the R outliers package. I would like to perform a
Q-test (Dixon test) on my data set. I used the dixon.test function, but I
cannot understand what is the confidence level used to perform the test. I
have n=101 (n= number of data). So, can I use directly dixon.test ? What
about qdixon and qtable functions?
thank you so much!
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2009 Jun 01
1
using "cochran.test()" as a "mcnemar.test()" ?
Hello all
I wish to perform a mcnemar.test() for a 5X5 matrix.
Wikipedia tells me (http://en.wikipedia.org/wiki/Cochran_test) I should turn
to cochran.test.
The only place I found it was in the "outliers" package, but the command
cochran.test() acts differently then mcnemar.test() , and doesn't take a
table as input.
Any ideas on how to use it ?
#Example code:
aa =
2007 Apr 09
1
How to solve differential and integral equation using R?
Hello,
I want to know if there are some functions or packages to solve differential
and integral equation using R.
Thanks.
Shao chunxuan.
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2004 Sep 23
6
detection of outliers
Hi,
this is both a statistical and a R question...
what would the best way / test to detect an outlier value among a series of 10 to 30 values ? for instance if we have the following dataset: 10,11,12,15,20,22,25,30,500 I d like to have a way to identify the last data as an outlier (only one direction). One way would be to calculate abs(mean - median) and if elevated (to what extent ?) delete the
2009 Jun 04
4
Cochran’s Q statistic
Does anyone know which package include the computation of Cochran’s Q
statistic in R?
jlfmssm
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2010 Sep 28
2
cochran Q test
Dear all,
I am trying to look for a built in function that performs the cochran Q
test.
that is, cochranq.test(X)
where X is a contingency table (maybe a matrix or data.frame).
The output will naturally be the test statisitcs, p-value, etc.
A quick search on Google gives me the cochran.test in the 'outlier' package,
but I had a look at the description of the test and it doesn't look
2000 Jul 11
1
q() problem and more.
Hi Rers,
W/o trying to make a long story short (I hope you read that correctly), I
have been working on a nice little R function ...
Somewhere along the line I got an error that refers to a max function in
my function (I think this is a vector vs. scalar issue):
Error in max(..., na.rm = na.rm) : invalid "mode" of argument
If that's not bad enough, even when I q() R and say
2006 Sep 18
1
Cochrans Q Test
Hi!
I would like to conduct a Cochran`s Q Test in R, but have not found any
suitable function.
My first idea was: J <- as.table(matrix(c(6,16,2,4),ncol=2, dimnames =
list("C" = c("Favorable","Unfavorable"),"Drug A Favorable"=c("B
Favorable","B Unfavorable"))))
L <- as.table(matrix(c(2,4,6,6),ncol=2, dimnames =
2007 Sep 22
1
rsync not running on IA64
I have built rsync on IA64 using Intel's 'icc' compiler and can run the
rsync executable interactively but when attempting to run under
'crontab' I get the following error:
+ /home/horace/mccssmb2/src/rsync-2.6.9/rsync -z --partial -v --progress
--recursive --stats --times --links
--exclude-from=/project/horace/mcc101/.rsync-EXCLUDE
--timeout=1200 /project/horace/mcc101