Re: [R] - detecting outliers
Hi, I believe that first learning the appropriate statistical methods to detect the outliers and searching for the related functions in R is a better way. Ozgur -- View this message in context: http://r.789695.n4.nabble.com/detecting-outliers-tp4632636p4632637.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] - detecting outliers
Hello,
Had you looked more, and you would have seen R-help discussions on what
is an outlier. Almost unanimously, an ill defined concept.
In your problem, predators don't eat all eggs that they are given except
for one case, 38 were given and all 38 were eaten. You can detect this
in R with
boxplot.stats(d$FR)
Or with the return value of boxplot. See ?boxplot
Hope this helps,
Rui Barradas
Em 07-06-2012 07:24, Joachim Audenaert escreveu:
Hello all,
I am estimating parameters for regression functions on experimental data.
Functional response of Rogers type II.
I would like to know which points of my dataset are outliers. What is the
best method to do this with R?
I found a method via R help, but would like to know if there are better
methods for my purpose.
Here is the script I us now:
library("mvoutlier")
dat <- read.delim("C:/data.txt")
uni.plot(dat)
My data looks like the following (copied into a txt file):
(N0 is the initial number of eggs fed to the predator, FR is the number of
eggs eaten by the predator during 24h)
N0 FR
37 30
27 15
36 14
37 13
45 8
25 0
47 20
34 6
25 8
21 7
24 24
34 17
23 10
29 5
38 38
24 24
20 17
14 8
18 15
15 10
26 5
33 5
22 21
38 3
22 20
23 19
20 6
20 4
21 18
25 5
13 13
9 8
8 4
7 7
8 5
11 9
Kind regards,
Met vriendelijke groeten,
Joachim
Don't waste paper! Think about the environment before printing this e-mail
__
Joachim Audenaert
Adviesdienst Gewasbescherming
Proefcentrum voor Sierteelt
Schaessestraat 18
B-9070 Destelbergen
Belgium
Tel. +32 9 353 94 71
Fax +32 9 353 94 95
E-mail: joachim.audena...@pcsierteelt.be
www.pcsierteelt.be
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Re: [R] - detecting outliers
Joachim Audenaert pcsierteelt.be> writes: > > Hello all, > > I am estimating parameters for regression functions on experimental data. > Functional response of Rogers type II. > > I would like to know which points of my dataset are outliers. What is the > best method to do this with R? The best method for detecting outliers really depends on the motivation/purpose. Your data look noisy, but by eye nothing really jumps out. Looking at a histogram (hist()) and Q-Q plot qqnorm() of the residuals of the fit, it looks like the distribution is slightly skewed but that there are no points that really fall very far outside a normal distribution (normality is not a necessity for making inferences from an nls fit, but it helps a lot) __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
[R] - detecting outliers
Hello all,
I am estimating parameters for regression functions on experimental data.
Functional response of Rogers type II.
I would like to know which points of my dataset are outliers. What is the
best method to do this with R?
I found a method via R help, but would like to know if there are better
methods for my purpose.
Here is the script I us now:
library("mvoutlier")
dat <- read.delim("C:/data.txt")
uni.plot(dat)
My data looks like the following (copied into a txt file):
(N0 is the initial number of eggs fed to the predator, FR is the number of
eggs eaten by the predator during 24h)
N0 FR
37 30
27 15
36 14
37 13
45 8
25 0
47 20
34 6
25 8
21 7
24 24
34 17
23 10
29 5
38 38
24 24
20 17
14 8
18 15
15 10
26 5
33 5
22 21
38 3
22 20
23 19
20 6
20 4
21 18
25 5
13 13
9 8
8 4
7 7
8 5
11 9
Kind regards,
Met vriendelijke groeten,
Joachim
Don't waste paper! Think about the environment before printing this e-mail
__
Joachim Audenaert
Adviesdienst Gewasbescherming
Proefcentrum voor Sierteelt
Schaessestraat 18
B-9070 Destelbergen
Belgium
Tel. +32 9 353 94 71
Fax +32 9 353 94 95
E-mail: joachim.audena...@pcsierteelt.be
www.pcsierteelt.be
__
[[alternative HTML version deleted]]
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
