Displaying 20 results from an estimated 500 matches similar to: "precision of gamma function"
2009 Jul 23
1
Changing ts times to dates
Dear all,
Ive just started with R and I have question:
how can you change a time from a ts object .i.e 2009.004 to "2009-01-01"? Is
there any function for this? I tried around with as.Date... but it hasnt
worked.
Thank you beforehand.
Chuse.
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2009 Jul 27
1
Conversion a ts time to another class.
Dear R collegues,
I am trying to change a ts time such as 2009.004 to a str or POSIX
class as "2009-01-01".
Is there any function or method to do it?. Thank you beforehand.
Chuse.
2011 Nov 18
3
Permutations
Hi all,
why factorial(150) shows the error out of range in 'gammafn'?
I have to calculate the number of subset formed by 150 samples taking 10 at
a time. How is this possible?
best
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2009 Oct 24
2
Implementation of gamma function for large number
Hi - I ran into a problem when the argument to gamma function is
large. Says, if I do the following:
> gamma(17000)
[1] Inf
Warning message:
value out of range in 'gammafn'
Is there anyway to get around this or other implementation? Thank you.
-rc
2011 Mar 02
1
Refine ARMA model
Dear users,
I tried to fit an AR(2) model to data. This the result:
> arima(vw,c(3,0,0))
Call:
arima(x = vw, order = c(3, 0, 0))
Coefficients:
ar1 ar2 ar3 intercept
0.1052 -0.0102 -0.1203 0.0099
s.e. 0.0337 0.0339 0.0338 0.0018
sigma^2 estimated as 0.002934: log likelihood = 1293.16, aic = -2576.33
Now, ar2 is not significantly different from
2005 Jun 14
3
Calling C from Fortran
I would like to call C routines from Fortran under linux as suggested in
section 5.6 of
the "Writing R extensions" documentation.
I'm familiar with Fortran but not with C.
I understand the example provided in Fortran:
subroutine testit()
double precision normrnd, x
call rndstart()
x = normrnd()
call dblepr("X was", 5, x, 1)
call rndend()
end
but I don't understand
2011 Feb 02
1
Acf of Frima
Hello,
I am trying to calculate the autocovariance matrix for any general
farima(p,d,q) with
p,q > 1. Could anyone give an idea how to implement in R or if there
is any package for this?
thank you beforehand.
Jose.
2007 Oct 26
5
help
hello,
please can anyone help me out. Am a new user of R
program. Am having problem
with this code below, not getting the expected
results.
1. Each m, the cumulative sum should be 1.000 but the
2nd and 3rd m returned 2.000 and 3.000
instead of 1.000.
2. to get the LCL(m) and UCL(m) for each m base on
these instructions
if out.cum > 0.025 then LCL(m)= y-1
if out.cum >0.975
2005 Jul 03
2
over/under flow
I am porting some FORTRAN to R in which an Inf triggers an if(). The
trigger is infinite on exp(lgamma(OVER)). What is the canonical R
style of determining OVER when exp(OVER)== Inf? The code structure
that I am
porting is best left intact--so I need to query R somehow to the value
of OVER that causes exp(lgamma(OVER)) to equal Inf.
On my system,
exp(lgamma(171)) is about first to equal Inf.
2009 Apr 22
2
integrate lgamma from 0 to Inf
Dear R users,
i try to integrate lgamma from 0 to Inf. But here i get the message "roundoff error is detected in the extrapolation table", if i use 1.0e120 instead of Inf the computation works, but this is against the suggestion of integrates help information to use Inf explicitly. Using stirlings approximation doesnt bring the solution too.
## Stirlings approximation
lgammaApprox
2006 Jul 22
1
ifelse command
Dear:
I try to revise the maximum likelihood function below using something constrains. But it seems something wrong with it. Becasue R would not allow me to edit the function like this. It is very appreciate if you can help.
function (parameters,y,x1,x2)
{
p<-parameters[1]
alpha1<-parameters[2]
beta1<-parameters[3)]
delta1<-parameters[4]
alpha2<-parameters[5]
1998 Sep 10
2
R-beta: trouble compiling 0.62.3 on SunOS 4.1.4: lgamma conflicts
I've recently tried to get 0.62.3 up on our Suns (4.1.4, using gcc; I'm
also having trouble with a Solaris 2.6 compile but I haven't given up hope
on that one yet) -- the last compile I did was 0.61.1, which worked
smoothly.
Running
./configure --prefix=/usr/local/apps/R/R-0.62.3 [--with-g77]
(tried both with and without g77, eventually get to the same place),
I get a conflict
2011 Aug 17
1
multinomRob - error message
Hi,
I would like to use the multinomRob function to test election results.
However, depending on which independent variables I include and how
many categories I have in the dependent variable, the model cannot be
estimated.
My data look like this (there are 68 observations):
> head(database)
RESTE09 GAUCHE09 PDC09 PLR09 UDC09 MCG09 RESTE05 GAUCHE05 PDC05
D1 1455
2007 Oct 29
2
help please
hello,
please can anyone help me out. Am a new user of R
program. Am having problem
with this code below, not getting the expected
results.
Each m, the cumulative sum should be 1.000 but the
2nd and 3rd m returned 2.000 and 3.000
instead of 1.000.
thanks
Aruike
pp=function(x,n,M){z=1.0;a=2.3071430;b=7.266064;H=3
out.h=c()
out.y=c()
out.m=c()
out.prob=c()
2008 Apr 18
3
help me to debug this part of code?
I am trying to solve the integration equation, for different values of K from
4 to 25, the integration is with respect to u,
Here is the equation: gamma(k/2) / ( sqrt(k-1)*gamma((k-1)/2) ) *
integrate(f= (1+u^2/k-1)^(-k/2), lower=0, upper= sqrt(a^2*k/(k+1-a^2)) ) =
the similar expression as te left hand except k becomes k+1
my code is below, I don't know why R keep telling me the syntax
2000 Oct 04
2
gamma and lgamma functions (PR#684)
The following seems very strange:
> lgamma(-0.04)
[1] 3.243307
> gamma(-0.04)
[1] -25.61830
Jim
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2014 Sep 22
2
Replace isnan and lgamma in Fortran subroutine in R package
Hello,
I submitted a package which used Fortran functions isnan and lgamma. However, I was told that:
isnan and lgamma are not Fortran 95 functions.
I was asked to write 'cross-platform portable code' and so should not be writing GNU extensions to Fortran.
See http://cran.r-project.org/web/checks/check_results_mpath.html, which will shortly show installation failures under Solaris.
I
2008 Oct 23
1
distribution fitting
Dear R-help readers,
I am writing to you in order to ask you a few questions about distribution
fitting in R.
I am trying to find out whether the set of event interarrival times that I
am currently analyzing is distributed with a Gamma or General Pareto
distribution. The event arrival granularity is in minutes and interarrival
times are in seconds, so the values I have are 0, 60, 120, 180, and
2010 Jul 05
2
Function to compute the multinomial beta function?
Dear R-users,
Is there an R function to compute the multinomial beta function? That is, the normalizing constant that arises in a Dirichlet distribution. For example, with three parameters the beta function is Beta(n1,n2,n2) = Gamma(n1)*Gamma(n2)*Gamma(n3)/Gamma(n1+n2+n3)
Thanks in advance for any assisstance.
Regards,
Greg
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2005 Dec 05
3
The gamma function and infinity
I have to calculate some formula like:
gamma(x)/(gamma(x+y)
and I observed that for relatively big values of x, R
returns infinity and so cannot compute the formula. Is
it possible to force R to give the real value of
gamma(x) instead of Inf ?
thanks