Displaying 20 results from an estimated 49 matches for "infti".
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2010 Apr 14
2
Gaussian Quadrature Numerical Integration In R
Hi All,
I am trying to use A Gaussian quadrature over the interval (-infty,infty) with weighting function W(x)=exp(-(x-mu)^2/sigma) to estimate an integral.
Is there a way to do it in R? Is there a function already implemented which uses such weighting function.
I have been searching in the statmode package and I found the function "gauss.quad(100, kind="hermite")" which uses
2011 Nov 06
2
how to use quadrature to integrate some complicated functions
Hello to all,
I am having trouble with intregrating a complicated uni-dimensional function
of the following form
Phi(x-a_1)*Phi(x-a_2)*...*Phi(x-a_{n-1})*phi(x-a_n).
Here n is about 5000, Phi is the cumulative distribution function of
standard normal,
phi is the density function of standard normal, and x ranges over
(-infty,infty).
My idea is to to use quadrature to handle this integral. But
2012 Feb 29
2
Converting a function from Splus to R
I have a function written for Splus, when I run it in R I obtain get an error
because the function has the elements "0.d0" and "2.d0". How can I change it
to run in R?
The function can be found in page 230 from
http://www.stat.wisc.edu/~mchung/teaching/stat471/stat_computing.pdf
Function is as follows:
gauher <- function(n) {# Gauss-Hermite: returns x,w so that
2009 Dec 06
5
optim with constraints
Hi, dear R users
I am a newbie in R and I wantto use the method of meximum likelihood
to fit a Weibull distribution to my survival data. I use "optim" as
follows:
optim(c(1, 0.25),weibull.like,mydata=mydata,method="L-BFGS-B",hessian
= TRUE)
My question is: how do I setup the constraints so that the two
parametrs of Weibull to be pisotive? Or should I use other function
2006 Oct 02
1
Trig.Rd typo (PR#9269)
Full_Name: Robin Hankin
Version: 2.4.0 RC
OS: MacOSX 10.4.7
Submission from: (NULL) (139.166.242.29)
The first cut line described in Trig.Rd for asin() is incorrect in the ascii
version of the manpage.
The Rd file reads:
For \code{asin()} and \code{acos()}, there are two cuts, both along
the real axis: \eqn{\left(-\infty, -1\right]}{\(-Inf, 1\]} and
Note the inconsistency between the
2012 May 23
1
numerical integration
Greetings,
Sorry, the last message was sent by mistake! Here it is again:
I encounter a strange problem computing some numerical integrals on [0,oo).
Define
$$
M_j(x)=exp(-jax)
$$
where $a=0.08$. We want to compute the $L^2([0,\infty))$-inner products
$$
A_{ij}:=(M_i,M_j)=\int_0^\infty M_i(x)M_j(x)dx
$$
Analytically we have
$$
A_{ij}=1/(a(i+j)).
$$
In the code below we compute the matrix
2010 Sep 21
3
bivariate vector numerical integration with infinite range
Dear list,
I'm seeking some advice regarding a particular numerical integration I
wish to perform.
The integrand f takes two real arguments x and y and returns a vector
of constant length N. The range of integration is [0, infty) for x and
[a,b] (finite) for y. Since the integrand has values in R^N I did not
find a built-in function to perform numerical quadrature, so I wrote
my own after
2006 Nov 18
1
Questions regarding "integrate" function
Hi there. Thanks for your time in advance.
I am using R 2.2.0 and OS: Windows XP.
My final goal is to calculate 1/2*integral of
(f1(x)^1/2-f2(x)^(1/2))^2dx (Latex codes:
$\frac{1}{2}\int^{{\infty}}_{\infty}
(\sqrt{f_1(x)}-\sqrt{f_2(x)})^2dx $.) where f1(x) and f2(x) are two
marginal densities.
My problem:
I have the following R codes using "adapt" package. Although "adapt"
2008 Mar 12
3
Types of quadrature
Dear R-users
I would like to integrate something like \int_k^\infty (1 - F(x)) dx, where F(.) is a cumulative distribution function. As mentioned in the "integrate" help-page: integrate(dnorm,0,20000) ## fails on many systems. This does not happen for an adaptive Simpson or Lobatto quadrature (cf. Matlab). Even though I am hardly familiar with numerical integration the implementation
2008 Jan 07
2
chi-squared with zero df (PR#10551)
Full_Name: Jerry W. Lewis
Version: 2.6.1
OS: Windows XP Professional
Submission from: (NULL) (24.147.191.250)
pchisq(0,0,ncp=lambda) returns 0 instead of exp(-lambda/2)
pchisq(x,0,ncp=lambda) returns NaN instead of exp(-lambda/2)*(1 +
SUM_{r=0}^infty ((lambda/2)^r / r!) pchisq(x, df + 2r))
qchisq(.7,0,ncp=1) returns 1.712252 instead of 0.701297103
qchisq(exp(-1/2),0,ncp=1) returns 1.238938
2003 Sep 16
1
calculation of the p value in ks.test()
Hi,
I'm working with the ks.test() function and I have also implemented
the test using Conover as the reference. My D value matches that
produced by R. However to calculate the p value I am using the code
described in Numerical Recipes in C++ (2nd Ed.) pg 631.
The p value produced by the NRC code is generally larger than that
produced by R by a factor of 10. Currently I am not in a position
2006 Nov 17
0
Question regarding "integrate" function
Hi there. Thanks for your time in advance.
My final goal is to calculate 1/2*integral of
(f1(x)^1/2-f2(x)^(1/2))^2dx (Latex codes:
$\frac{1}{2}\int^{{\infty}}_{\infty} (\sqrt{f_1(x)}-\sqrt{f_2(x)})^2dx
$.) where f1(x) and f2(x) are two estimated marginal densities.
My problem:
I have the following R codes using "adapt" package. Although "adapt"
function is mainly designed
2006 Nov 17
0
questions regarding "integrate" function in R
Hi there. Thanks for your time in advance.
My final goal is to calculate 1/2*integral of
(f1(x)^1/2-f2(x)^(1/2))^2dx (Latex codes:
$\frac{1}{2}\int^{{\infty}}_{\infty}
(\sqrt{f_1(x)}-\sqrt{f_2(x)})^2dx $.) where f1(x) and f2(x) are two
marginal densities.
My problem:
I have the following R codes using "adapt" package. Although "adapt"
function is mainly designed for more
2009 Dec 10
1
MLE for a t distribution
Given X1,...,Xn ~ t_k(mu,sigma) student t distribution with k degrees
of freedom, mean mu and standard deviation sigma, I want to obtain the
MLEs of the three parameters (mu, sigma and k). When I try traditional
optimization techniques I don't find the MLEs. Usually I just get
k->infty. Does anybody know of any algorithms/functions in R that can
help me obtain the MLEs? I am especially
2010 May 10
1
Polylogarithm
I am writing to ask if R has a build- in function to calculate this
polylogarithm Li_n(z) function , also known as the Jonqui?re's function
defined as
Li_n(z)=sum_(k=1)^infty(z^k)/(k^n)
Thanks
Andy
2002 Dec 01
1
SYSLINUX COM32 example in assembly (NASM)
Hello
Where can I get example in assembly, using COM32 API ?
I'm trying to make simple "Hello World" using COM32, but this code does not
works 8-(
org 0x101000 ; this number I get from comboot.doc
_start:
mov ecx,msge-msg
mov ebx,msg
mov ah,0x02
.L:
mov dl, byte [ebx]
inc ebx
int 0x21
loop .L
.Z: jmp .Z ; \infty loop
msg: db "Hello World !"
msge:
2012 May 23
0
numerical integrals
Greetings,
I encounter a strange problem computing some numerical integrals on [0,oo).
Define
$$
M_j(x)=exp(-jax)
$$
where $a=0.08$. We want to compute the $L^2([0,\infty))$-inner products
$$
A_{ij}:=(M_i,M_j)=\int_0^\infty M_i(x)M_j(x)dx
$$
Analytically we have
$$
A_{ij}=1/(a(i+j)).
$$
In the code below we compute the matrix $A_{i,j}$, $1\leq i,j\leq 5$, numerically
and check against the known
1997 Jul 28
0
R-alpha: R 0.50.a1: patch for NChisquare documentation
The patch below fixes the NChisquare documentation problem that I've
been mentioning for some time now.
NOTE: There is one DEQN where the LaTeX part contains real LaTeX code,
because I did not see how to get a sum sign (and a roman math font)
otherwise. Seems to work, though ... MARTIN?
-k
**********************************************************************
***
2011 Mar 16
2
Re; Fitting a Beta distribution
I want to fit some p-values to a beta distribution. But the problem is some
of the values have 0s and 1's. I am getting an error if I use the MASS
function to do this. Is there anyway to get around this?
--
Thanks,
Jim.
[[alternative HTML version deleted]]
2006 Jun 04
3
Absolutize URLs in a string
I wonder - do we have some helper/processor/gem to automatically
convert all URLs in a passed string to their canonical equivalent -
i.e. with the protocol, host and such prepended based on the Rails
environment. Super-duper infty for RSS feeds (I hate their
requirement for canonical URLs everywhere).
--
Julian ''Julik'' Tarkhanov
please send all personal mail to
me at