Displaying 20 results from an estimated 1000 matches similar to: "Re: Testing for normality of residuals in a regression model"
2004 Oct 26
3
Combining columns of different length
Hi,
you can use this simple function:
add.col<-function(df, new.col) {n.row<-dim(df)[1]
length(new.col)<-n.row
cbind(df, new.col)
}
see this example:
> x<-cbind(c(1,2,3),c(4,5,6))
> x
[,1] [,2]
[1,] 1 4
[2,] 2 5
[3,] 3 6
> y<-c(7,8)
> y
[1] 7 8
> add.col<-function(df, new.col)
2004 Jul 21
2
Testing autocorrelation & heteroskedasticity of residuals in ts
Hi,
I'm dealing with time series. I usually use stl() to
estimate trend, stagionality and residuals. I test for
normality of residuals using shapiro.test(), but I
can't test for autocorrelation and heteroskedasticity.
Is there a way to perform Durbin-Watson test and
Breusch-Pagan test (or other simalar tests) for time
series?
I find dwtest() and bptest() in the package lmtest,
but it
2004 Oct 20
2
R & Graphs
Dear R-users,
I'm finding for a R-package concerning graphs. Is
there some kind of that package? I've a set of
correlation coeffients between several variable and I
wish to built a graph to link variables correlated.
Many thanks.
Best,
Vito
=====
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"The business of the statistician is to catalyze
the scientific learning process."
George
2004 Nov 15
1
R: how can draw probability density plot?
I hope this example could help you
best
vito
> x<-seq(-3.5,3.5,0.1)
> x
[1] -3.5 -3.4 -3.3 -3.2 -3.1 -3.0 -2.9 -2.8 -2.7 -2.6
-2.5 -2.4 -2.3 -2.2 -2.1
[16] -2.0 -1.9 -1.8 -1.7 -1.6 -1.5 -1.4 -1.3 -1.2 -1.1
-1.0 -0.9 -0.8 -0.7 -0.6
[31] -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3 0.4
0.5 0.6 0.7 0.8 0.9
[46] 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9
2.0 2.1 2.2 2.3
2004 Oct 22
3
Convert a list in a dataframe
Hi,
I've a list containing parameters (intercepts &
coefficients) of 12 regressions fitted
> coeff
[[1]]
(Intercept) anno
-427017.1740 217.0588
[[2]]
(Intercept) anno
-39625.82146 21.78025
.....
[[12]]
(Intercept) anno
257605.0343 -129.7646
I want create a data frame with two columns (intercept
and anno)using data in these list.
Any help
2004 Jul 06
1
R & DataMining
Dear R-user,
I wish to know if someone is using R as concern
Datamining or KDD (Knowledge Discovery in Database)
and if already exists a R package specialized in this
kind of analysis.
I found this contributes on the R web site:
[20] Diego Kuonen. Introduction au data mining avec R
: vers la reconqu??te du `knowledge discovery in
databases' par les statisticiens. Bulletin of the
Swiss
2004 Oct 08
1
Correlation Matrix
Hi,
I'm dealing with a datamining analysis: I've a lot of
categories of product sold per week (n. week =26, n.
categories about 50.
my dataframe is like this:
Settimana ALIMENTI..ALTRI. ALIMENTI.APROTEICI
1 1 3 19
2 2 2 0
3 3 1 22
4 4 2
2004 Nov 12
1
How to get mode in case of discrete or categorial data
Dear all,
in a previuos message was asked how get the mode of
continous distribution. Now I'm asking if there an R
function to obtain the mode in case of a discrete
distribution or categorial data. The only way is to
use table():
> x<-rep(1:5,100)
> s<-sample(x,40)
> t<-table(s)
> t
s
1 2 3 4 5
13 10 5 4 8
the mode is value=1
Thanks
Cordially
Vito
=====
2004 Sep 21
0
S/R and data mining (was can't understand "R")
Hi Thomas,
see these papers or books (some are available on the
web):
Diego Kuonen, Introduction au data mining avec R :
vers la reconqu??te du `knowledge discovery in
databases' par les statisticiens. Bulletin of the
Swiss Statistical Society, 40:3-7, 2001.
Consultabile all??indirizzo web:
http://www.statoo.com/en/publications/2001.R.SSS.40/
Diego Kuonen and Reinhard Furrer, Data mining
2004 Nov 10
1
Loading some function at R startup
Dear R-users,
I've built these functions usefell for me to
import/export data from/to Excel:
importa.da.excel<-function(){read.delim2("clipboard",
dec=",")
## questa funzione consente di importare dati da Excel
in R
## selezionare in Excel le celle che contengono i
dati,
## compresi in nomi delle colonne
## Autore: Vito Ricci email:vito_ricci at yahoo.com
## Data di
2004 Jul 07
1
Daily time series
Hi,
I'm dealing with time series with 1 observaton for day
(data sampled daily). I will create a ts object using
that time series and the function ts().
In ts() help is written:
The value of argument 'frequency' is used when the
series is sampled an integral number of times in each
unit time interval. For example, one could use a value
of '7' for 'frequency' when
2004 Oct 27
2
Skewness and Kurtosis
Hi,
in which R-package I could find skewness and kurtosis
measures for a distribution?
I built some functions:
gamma1<-function(x)
{
m=mean(x)
n=length(x)
s=sqrt(var(x))
m3=sum((x-m)^3)/n
g1=m3/(s^3)
return(g1)
}
skewness<-function(x)
{
m=mean(x)
me=median(x)
s=sqrt(var(x))
sk=(m-me)/s
return(sk)
}
bowley<-function(x)
{
q<-as.vector(quantile(x,prob=c(.25,.50,.75)))
2004 Nov 22
1
R: simulation of Gumbel copulas
Hi,
I found this document, but it concerns S+. If it could
interest you'll see:
http://faculty.washington.edu/ezivot/book/QuanCopula.pdf
Cordially
Vito
You wrote:
Dear R:
Is there a function or a reference to simulate Gumbel
copulas, please?
Thanks in advance!
Sincerely,
Erin Hodgess
mailto: hodgess at gator.uhd.edu
R version 2.0.1 windows
=====
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2004 Nov 12
4
Mode in case of discrete or categorial data
Thanking John for his suggestion I build this function
which get the mode of both categorial and discrete
data.
Mode<-function(x){t<-table(x)
if (is.numeric(x)) as.numeric(names(t)[t == max(t)])
else (names(t)[t == max(t)])
}
Any other improvement and suggestion will welcome.
Best
Vito
> s
[1] 1 1 6 1 1 7 6 5 6 2 1 4 5 6 6 7 3 5 4 1 7 3 7 3 3
7 7 2 1 4 4 2 7 7 6 6 1 2
[39] 5 1 7 7
2005 Feb 07
0
R: Creating a correlation Matrix
Hi,
see ?cor in base package to get correlation matrix for
your data. Maybe it could be usefull getting principal
components (give a look to: ? princomp (base)) to
reduce the number of variables.
Hoping I helped you.
Best regards,
Vito
You wrote:
Hi all:
I have a question on how to go about creating a
correlation matrix. I have
a huge amount of data....21 variables for 3471 times.
I want
2004 Nov 25
2
R vs SPSS
Dear all,
in last weeks you discussed about R vs SAS.
I want to ask your opinion about a comparison between
R and SPSS. I don't know this software, but some weeks
ago I went to a presentation of this product. I found
it really user-friendly with GUI (even if I'd prefer
command line) and very usefull and simple to use in
creation and managing tables, OLAP tecniques, pivot
table.
What you
2004 Nov 29
0
Ts analysis with R: a contribute in Italian language
Dear All,
I wish to inform, especially Italian speaking R-users,
that on CRAN web site is now available a contribute
(in Italian language) about using R in ts analysis.
Any comments would be appreciated.
Best regards,
Vito
=====
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Became solutions' constructors
"The business of the statistician is to catalyze
the scientific learning process."
2004 Dec 03
0
R: vector to matrix transformation
Hi,
did you see:
as.data.frame()
as.matrix()
as.vector()
matrix()
> x
a b c
1 1 2 3
2 1 2 3
3 2 3 4
4 3 4 5
> is.data.frame(x)
[1] TRUE
> as.matrix(x)
a b c
1 1 2 3
2 1 2 3
3 2 3 4
4 3 4 5
> y<-as.matrix(x)
> is.matrix(y)
[1] TRUE
> as.vector(y)
[1] 1 1 2 3 2 2 3 4 3 3 4 5
> z<-as.vector(y)
> m<-matrix(z,ncol=3)
> m
[,1] [,2] [,3]
[1,] 1 2
2005 Jan 20
0
Re: suggestion on data mining book using R
Hi,
see these links:
http://www.liacc.up.pt/~ltorgo/DataMiningWithR/
http://sawww.epfl.ch/SIC/SA/publications/FI01/fi-sp-1/sp-1-page45.html
Brian D. Ripley, Datamining: Large Databases and
Methods, in Proceedings of "useR! 2004 - The R User
Conference", may 2004
http://www.ci.tuwien.ac.at/Conferences/useR-2004/Keynotes/Ripley.pdf
looking for a book I suggest:
Trevor Hastie , Robert
2005 Jan 21
0
R: chi-Squared distribution
Hi,
Attention chi-squared distribution, unlike F
distribution, has only df1 as parameter, not df1 and
df2. So correct into:
outer(1:3, 1:3, function(df1, df2) qchisq(0.95, df1,
df2))
outer(1:3, 1:3, function(df1, df2) qchisq(0.95, df1))
^^^^^^^^^^^^^^^^^^^^
Regards,
Vito
you wrote:
Dear Rs:
outer(1:3, 1:3, function(df1, df2) qf(0.95, df1, df2))
I compare this F