Displaying 20 results from an estimated 3000 matches similar to: "Fitting distribution with R: a contribute"
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
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 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 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 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 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 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 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
=====
Diventare costruttori di soluzioni
"The business of the statistician is to catalyze
the scientific learning process."
George
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
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
=====
Diventare costruttori di soluzioni
2004 Dec 02
1
Re: A somewhat off the line question to a log normal distribution
Dear Siegfried,
I believe your boss is wrong saying that:
>He also tried to explain me that the monthly means
>(based on the daily measurements) must follow a
>log-normal distribution too then over the course of a
year.
every statistician know that increasing the sample
size the sample distribution of the mean is proxy to a
gaussian distribution (Central Limit Theorem)
independently
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 Nov 17
1
R: log-normal distribution and shapiro test
Hi,
from what you're writing:
"The logaritmic transformation
"shapiro.test(log10(y))" says: W=0.9773, p-value=
2.512e-05." it seems the log-values are not
distributed normally and so original data are not
distributed like a log-normal: the p-value is
extremally small!
Other tests for normality are available in package:
nortest
compare the log-transformation of your ecdf
2004 Jul 07
7
Importing an Excel file
Hello, R users,
I am a very beginner of R and tried read.csv to import an excel file after
saving an excel file as csv. But it added alternating rows of fictitious NA
values after row number 16. When I applied read.delim, there were trailing
several commas at the end of each row after row number 16 instead of NA
values. Appreciate your help.
Kyong
[[alternative HTML version deleted]]
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
=====
Diventare costruttori di soluzioni
Became solutions' constructors
"The business of the statistician is to catalyze
the
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 Feb 23
1
nonlinear least square fit of an unknown function
Hi, I have a set of twelve points and wonder how I can
get a function that can then be used to calculate the
area under the curve (most important). Thanks.
Eric
2005 Feb 22
2
estimate the parameter of exponential distribution, etc.
Given a numeric vector of observations, does R have any generic way to estimate the parameters of commonly used distributions (exponential, gamma, etc.) without numerically optimizing the likelihood function?
Thanks,
David
_______________________________________
David R. Bickel http://davidbickel.com
Research Scientist
Pioneer Hi-Bred International
Bioinformatics & Exploratory Research
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