Displaying 20 results from an estimated 300 matches similar to: "underflow handling in besselK (PR#2179)"
2007 Jun 14
1
besselK
Assistance,
besselK- complex number problem
Im a student intrested in using R in my learning and research work in option pricing however i have a problem with besselK function In R.
Would you assit me in computing the besselK of third kind of a complex number in R.
Any code or suggestion will be highly appriceiated
eg
besselK(2,10) works well.. but
besselK(2,10i) doesnt work !!
im
2007 Jun 14
0
besselK- complex number problem any help is welcome
Assistance,
Im a student intrested in using R in my learning and research work in option pricing however i have a problem with besselK function In R.
Would you assit me in computing the besselK of third kind of a complex number in R.
Any code or suggestion will be highly appriceiated
eg
besselK(2,10) works well.. but
besselK(2,10i) doesnt work !!
im supprised it works in MATLAB but NOT
2010 Feb 11
1
Fwd: Recall function: "evaluation nested too deeply: infinite recursion / options(expressions=)?"
hello all
i searched the archives and couldn't get a solution to the following question.
i have the following function:
F=function(z,v)
{
if (v==-.5) return(1) else return(2*v/z + 1/Recall(z,v-1))
}
and while testing whether it works (ie F(z,v) is approx = besselK(z,1+v)/besselK(z,V). the recursion formula allows one to calculate besselK(z,1+v)/besselK(z,V) for large values of z )
2008 Nov 24
0
[R] besselK
[cc'ing to R-devel]
It's moderately obscure to me too, but ...
There are two sets of bessel code in the package, one
in C++ from Chris Bond and the other in FORTRAN from Netlib
(I think). The FORTRAN code is the one that's giving trouble,
you might try just removing the FORTRAN code from the src
directory and trying again.
2009 Nov 20
1
Bessel function with large index value
I am looking for a method of dealing with the modified Bessel function
K_\nu(x) for large \nu.
The besselK function implementation of this allows for dealing with
large values of x by allowing for exponential scaling, but there is no
facility for dealing with large \nu.
What would work for me would be an lbesselK function in the manner of
lgamma which returned the log of K_\nu(x) for large
2007 Jun 18
1
two bessel function bugs for nu<0
#bug 1: besselI() for nu<0 and expon.scaled=TRUE
#tested with R-devel (2007-06-17 r41981)
x <- 2.3
nu <- -0.4
print(paste(besselI(x, nu, TRUE), "=", exp(-x)*besselI(x, nu, FALSE)))
#fix:
#$ diff bessel_i_old.c bessel_i_new.c
#57c57
#< bessel_k(x, -alpha, expo) * ((ize == 1)? 2. : 2.*exp(-x))/M_PI
#---
#> bessel_k(x, -alpha, expo) * ((ize == 1)? 2. :
2004 Oct 10
1
Modified Bessel function (third kind)
Hi:
There is a Modified Bessel function (third kind,
real order) besselK in R. Is there a C version of this
function?
I can only find a Fortran function rkbesel on
http://www.netlib.org/specfun/. However, this rkbesel
fortran function is the second kind.
Thank you!
liu
_______________________________
Declare Yourself - Register online to vote today!
2005 Aug 09
0
qpois minor bug (PR#8058)
Full_Name: Mikael Weigelt
Version: 2.0
OS: windows
Submission from: (NULL) (207.171.180.101)
The calculation of the qpois attempts to use the Cornish-Fisher expansion as a
starting approximation. The definition of the expansion is incorrect. However,
since this approximation just gives an initial solution, the end result of the
function is still correct.
To fix the approximation, in the
2010 Feb 11
0
Recall function: "evaluation nested too deeply: infinite recursion / options(expressions=)?"
hello all
i searched the archives and couldn't get a solution to the following question.
i have the following function:
F=function(z,v)
{
if (v==-.5) return(1) else return(2*v/z + 1/Recall(z,v-1))
}
and while testing whether it works (ie F(z,v) is approx = besselK(z,1+v)/besselK(z,V). the recursion formula allows one to calculate besselK(z,1+v)/besselK(z,V) for large values of z )
2019 Dec 09
0
What should dnorm(0, 0, -Inf) return?
>>>>> peter dalgaard
>>>>> on Sun, 8 Dec 2019 12:11:50 +0100 writes:
> Yes, that looks like a bug and an easily fixable one too.
agreed.
> However, I spy another issue: Why do we check the
> !R_FINITE(x) && mu == x before checking for sd < 0 ? The
> difference is whether we
> return ML_NAN; or ML_ERR_return_NAN;
2019 Dec 08
2
What should dnorm(0, 0, -Inf) return?
Yes, that looks like a bug and an easily fixable one too.
However, I spy another issue: Why do we check the !R_FINITE(x) && mu == x before checking for sd < 0 ? The difference is whether we
return ML_NAN;
or
ML_ERR_return_NAN;
but surely negative sd should always be an error?
I'd be inclined to do
if (sigma < 0) ML_ERR_return_NAN;
if(!R_FINITE(sigma)) return R_D__0;
2002 Dec 11
3
Modified Bessel Function - 2nd kind
In order to fit a probability distribution proposed by Sichel [Journal of
the Royal Statistical Society. Series A (General), Vol. 137,
No. 1. (1974), pp. 25-34], I need a modified Bessel function of the 2nd
kind. I notice that the base package of "R" only has modified Bessel
functions of the 1st and 3rd kind. Does a modified Bessel function of the
2nd kind exist anywhere?
Many
2002 Nov 26
2
Existence of non-vectorised functions
Dear R-Group:
Recently, I ran into a problem. I was using a function called "I.1",
which evaluates the first-order modified Bessel function of the first
kind, in the package "CircStats". This function is not vectorized,
since it uses a couple of "if" conditions. However, when I called this
function with a vector argument, I got no error/warning messages in
2002 Nov 01
8
R-1.6.1 is released
I've rolled up R-1.6.1.tgz a short while ago. This is a minor upgrade,
fixing an assortment of minor bugs, and one major one: 1.6.0
introduced a memory leak in deparsing, causing much trouble for people
running simulations.
You can get it from the developer site at
http://cvs.r-project.org/pub/CRAN/src/base/R-1.6.1.tgz
or wait for it to be mirrored at a CRAN site near you. Binaries for
2002 Nov 01
8
R-1.6.1 is released
I've rolled up R-1.6.1.tgz a short while ago. This is a minor upgrade,
fixing an assortment of minor bugs, and one major one: 1.6.0
introduced a memory leak in deparsing, causing much trouble for people
running simulations.
You can get it from the developer site at
http://cvs.r-project.org/pub/CRAN/src/base/R-1.6.1.tgz
or wait for it to be mirrored at a CRAN site near you. Binaries for
2019 Dec 07
0
What should dnorm(0, 0, -Inf) return?
Good question, I cannot speak for R's developers but I would like to
provide some information on the problem. Here are the first few lines of
the dnorm function located at src\nmath\dnorm.c:
```
double dnorm4(double x, double mu, double sigma, int give_log)
{
#ifdef IEEE_754
if (ISNAN(x) || ISNAN(mu) || ISNAN(sigma))
return x + mu + sigma;
#endif
if(!R_FINITE(sigma)) return R_D__0;
2005 Apr 07
0
R 2.1.0 (beta) on IRIX
I'm trying to compile R-beta on IRIX using the native MipsPro 7.4
compilers, without great satisfaction. A list of problems is given
below, and any advice on solving them is appreciated.
Martyn
Configuration:
-------------
Here are the configuration options I am using
./configure CC=cc CXX=CC F77=f77 CPPFLAGS="-I/usr/freeware/include"
LDFLAGS="-L/usr/freeware/lib32"
2006 Aug 28
1
Modified Bessel function of third kind (fractional or real order)
Hello,
I am searching for code in C++ or fortran for Modified Bessel function of third kind (fractional or real order). Can someone help me?
Thank you
---------------------------------
Découvrez un nouveau moyen de poser toutes vos questions quelque soit le sujet ! Yahoo! Questions/Réponses pour partager vos connaissances, vos opinions et vos expériences. Cliquez ici.
2000 Jan 19
1
Segmentation fault using integrate()
Hi all,
Running R 0.90.1 on a RH 6.1 system. Installation of the
integrate_2.1-2 package went smoothly. My code contains a loop
in which integrate() is called several times in each pass.
I get a segmentation fault after what seems to be a random number
of calls to integrate(). Debug output shows:
Program received signal SIGSEGV, Segmentation fault.
promiseArgs (el=0x40276414,
2009 Mar 17
3
R does not compile any more on FreeBSD 8.0-CURRENT
On a recent FreeBSD 8.0-CURRENT (i386) building R (any version) breaks
with the following messages:
----------------------------------------------------------------------
[...snip...]
gcc -std=gnu99 -I. -I../../src/include -I../../src/include
-I/usr/local/include -DHAVE_CONFIG_H -g -O2 -c wilcox.c -o wilcox.o
gcc -std=gnu99 -I. -I../../src/include -I../../src/include
-I/usr/local/include