Displaying 20 results from an estimated 9000 matches similar to: "Outlier colors in image()"
2010 Jan 06
1
How do I upside down colorkey of levelplot?
Hi, all.
I made the main figure of levelplot upside down by transposing and
proper indexing; upper left corner is the biginning of matrix.
However, I can't figure out how I can upside down the vertical
colorkey right side of the main figure.
Any help will be greatly appreciated.
Minho
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
2008 Oct 13
0
stl outlier help request
Currently I find that if I call stl() repeatedly I can use the weights array that is part of the stil output to detect outliers. I also find that if I repeatedly call stl() (replacing the outliers after each call) that the "remainder" portion of the stil output gets reduced. I am calling it like:
for(.index in 1:4)
{
st <- stl(mt, s.window=frequency(mt), robust=TRUE)
2004 May 26
0
Outlier identification according to Hardin & Rocke (1999)
I'm trying to use a paper by Hardin & Rocke: http://handel.cipic.ucdavis.edu/~dmrocke/Robdist5.pdf
as a guide for a function to identify outliers in multivariate data. Attached below is a function that is my attempt to reproduce their method and also a test to see what fraction of the data are identified as outliers. Using this function I am able to reproduce their results regarding the
2009 Jan 26
2
heatmap with levelplot
Hi there,
I'd like to create a heatmap from my matrix with
a) a defined color range (lets say from yellow to red)
b) using striking colors above and below a certain threshold (above = "green",
below = "blue")
Example matrix (there should be a few outliers generated...) + simple levelplot
without outliers marked:
library(lattice)
my.mat <- matrix(rnorm(800), nrow =
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)
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.
2011 May 04
1
Outlier removal by Principal Component Analysis : error message
Hi,
I am currently analysis Raman spectroscopic data with the hyperSpec package.
I consulted the documentation on this package and I found an example
work-flow dedicated to Raman spectroscopy (see the address :
http://hyperspec.r-forge.r-project.org/chondro.pdf)
I am currently trying to remove outliers thanks to PCA just as they did in
the documentation, but I get a message error I can't
2006 Mar 14
2
bwplot and outlier symbols
Hi,
I was just trying to figure out how to beautify the output of my
bwplot-output. Altogether I figured most of the things out on my own. The
one thing which puzzles me though are the symbols for the outliers.
I can easily change the form of the median symbol by using "pch" but I
don't know how to do this for outliers. Obviously the "outpch" of the
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
2012 Aug 03
1
outlier detection
I have a large set of data from an experiment in which each individual has trials 1-40 with approx. 150 points sampled every 0.1 sec within each trial. Each trial is a column and the rows are organized by time. I know there is a code to take out single outliers within a certain trial by using the chi square test code. But, I want to be able to determine if trials are outliers. I am having a tough
2008 Oct 28
1
Saving a 3d array into a matlab file
Dear R users,
I am tryting to save an 3d array to a matlab file like the following.
A <- array(1:24, c(2,3,4))
writeMat(filename, A=A)
But if I load the mat file from Matlab, it is not 3d matrix anymore.
Does anyone know how I can preserve the 3d structure?
Any help will be greatly appreciated.
Minho Chae
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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
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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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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2004 Jan 21
1
outlier identification: is there a redundancy-invariant substitution for mahalanobis distances?
Dear R-experts,
Searching the help archives I found a recommendation to do multivariate
outlier identification by mahalanobis distances based on a robustly estimated
covariance matrix and compare the resulting distances to a chi^2-distribution
with p (number of your variables) degrees of freedom. I understand that
compared to euclidean distances this has the advantage of being scale-invariant.
2012 Oct 31
1
gauss fit with outlier removal
I have distribution that are gaussian to a good approximation. I fit a
gaussian to these distributons. Once in a while there is an outlier. Could
someone suggest a robust method (R package already?) that removes those
outliers and redoes the gaussian fit to get a better fit? Thanks.
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2011 Dec 22
1
levelplot + cut() for custom color palette
I have the following data as input, from which I would like to make a lattice levelplot:
-----------------
x y level
1 m3134 m3134 1.0000000
2 m3134 m416B 0.4189057
3 m416B m3134 0.2696508
4 m3134 mA20 0.3322170
5 mA20 m3134 0.2454191
6 m3134 mB 0.3176792
...
-----------------
I transform the levels as follows, so that
2003 Jun 17
2
outlier
Hi,
I want to calculate the R-squared between two variables. Can you advice me how to identify and remove the outliers before performing R-squared calculation?
Thanks,
Kan
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2009 Aug 11
0
outlier detection test for large data set
Hello,
Which outlier detection test is robust for large dataset ?
I think the detection test in the package 'outliers' are suitable for small data set (between 3 and 100).
Do you know one for 20000 or more values ?
Thanks,
- Martial
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