Displaying 20 results from an estimated 1000 matches similar to: "R: chi-Squared distribution"
2005 Jan 21
0
R: chi-Squared distribution in Friedman test
Hi,
pchisq -> distribution function
dchisq -> density function
pval is the area under the curve, to calculte it you
use distribution function which is the integral of
density function. See:
http://www.itl.nist.gov/div898/handbook/eda/section3/eda362.htm
http://mathworld.wolfram.com/DistributionFunction.html
f(x) density function
F(x) distribution function =Pr(X<x)= integral(f(x))
2005 Jan 21
2
chi-Squared distribution
Dear Rs:
outer(1:3, 1:3, function(df1, df2) qf(0.95, df1, df2))
I compare this F distribution results with the table, the answers were perfect. But I need to see for chi-sqaured distribution. When I employed the similar formula
outer(1:3, 1:3, function(df1, df2) qchisq(0.95, df1, df2)) , I am getting unexpected results. I need to see the following values:
p=0.750 .....
1 1.323
2005 Jan 21
2
chi-Squared distribution in Friedman test
Dear R helpers:
Thanks for the previous reply. I am using Friedman racing test. According the the book "Pratical Nonprametric Statistic" by WJ Conover, after computing the statistics, he suggested to use chi-squared or F distribution to accept or reject null hypothesis. After looking into the source code, I found that R uses chi-sqaured distribution as below:
PVAL <-
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 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 24
0
R: text miner:
See:
http://wwwpeople.unil.ch/jean-pierre.mueller/
ttda - tools for textual data analysis
Regards
Vito
you wrote:
Hi,
Does a text miner exist in R-language similar to Splus
miner or SAS text
miner?
I would appreciate any information.
TIA,
Aldi
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2005 Feb 17
0
Fitting distributions
Dear UseRs,
I'm glad to inform that an English version of my
contribute concerning fitting distributions is now
available on CRAN:
http://cran.r-project.org/doc/contrib/Ricci-distributions-en.pdf
Any comments will be appreciated.
Best regards,
Vito
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Diventare costruttori di soluzioni
Became solutions' constructors
"The business of the statistician is to catalyze
the
2005 Jan 13
1
Re:Time-Series
Hi,
you can address to a single ts in a multivariate ts
object by namets[,index]. See this example:
> dati
X Y
1 100 200
2 150 210
3 180 220
4 200 230
5 220 250
> serie<-ts(dati,start=1999)
> serie
Time Series:
Start = 1999
End = 2003
Frequency = 1
X Y
1999 100 200
2000 150 210
2001 180 220
2002 200 230
2003 220 250
> serie[,1] ## first ts
Time Series:
Start =
2005 Jan 25
1
Fitting distribution with R: a contribute
Dear R-useRs,
I've written a contribute (in Italian language)
concering fitting distribution with R. I believe it
could be usefull for someones. It's available on CRAN
web-site:
http://cran.r-project.org/doc/contrib/Ricci-distribuzioni.pdf
Here's the abstract:
This paper deals with distribution fitting using R
environment for statistical computing. It treats
briefly some
2005 Jul 08
1
Orthogonal regression
Dear R-Users,
is there any statement to fit a orthogonal regression
in R environment?
Many thanks in advance.
Best regards,
Vito
Diventare costruttori di soluzioni
Became solutions' constructors
"The business of the statistician is to catalyze
the scientific learning process."
George E. P. Box
"Statistical thinking will one day be as necessary for efficient
2005 Aug 03
0
regression data set
Hi,
I suggest to give a look to:
?Practical Regression and Anova using R? by Julian
Faraway
http://cran.r-project.org/doc/contrib/Faraway-PRA.pdf
http://www.stat.lsa.umich.edu/~faraway/book/
see also package faraway for datasets:
http://cbio.uct.ac.za/CRAN/src/contrib/Descriptions/faraway.html
for some econometric data sets:
http://www.oswego.edu/~kane/econometrics/data.htm
for data sets:
2005 Nov 17
3
ECDF values
Dear UseRs,
maybe is a silly question: how can I get Empirical CDF
values from an object created with ecdf()?? Using
print I obtain:
Empirical CDF
Call: ecdf(t)
x[1:57] = 4.1, 4.4, 4.5, ..., 491.3,
671.27
Thanks in advance.
Regards,
Vito
Diventare costruttori di soluzioni
Became solutions' constructors
"The business of the statistician is to catalyze
the scientific
2005 Jan 13
2
chisq.test() as a goodness of fit test
Dear R-Users,
How can I use chisq.test() as a goodness of fit test?
Reading man-page I?ve some doubts that kind of test is
available with this statement. Am I wrong?
X2=sum((O-E)^2)/E)
O=empirical frequencies
E=expected freq. calculated with the model (such as
normal distribution)
See:
http://www.itl.nist.gov/div898/handbook/eda/section3/eda35f.htm
for X2 used as a goodness of fit test.
Any
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 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
=====
Diventare costruttori di soluzioni
Became solutions' constructors
"The business of the statistician is to catalyze
the scientific learning process."
2005 Jan 28
3
GLM fitting
DeaR R-useRs,
I'm trying to fit a logist model with these data:
> dati
y x
1 1 37
2 1 35
3 1 33
4 1 40
5 1 45
6 1 41
7 1 42
8 0 20
9 0 21
10 0 25
11 0 27
12 0 29
13 0 18
I use glm(), having this output:
> g<-glm(y~x,family=binomial,data=dati)
Warning messages:
1: Algorithm did not converge in: glm.fit(x = X, y =
Y, weights = weights, start = start, etastart =
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 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