Displaying 20 results from an estimated 200 matches similar to: "RFC: lchoose() vs lfactorial() etc"
2011 May 09
1
Stirlings Approximation
I have some big combinations like:
4444444444444444444444444444 choose 784645433
Can R compute these?
Is there any package that does stirlings approximation in R?
--
Thanks,
Jim.
[[alternative HTML version deleted]]
2010 Dec 15
1
lmList and lapply(... lm) different std. errors
Am I trying to perform multiple linear regressions on each 'VARIABLE2'. I
figured out that there are different ways, using the following code: (data
is given at the end of this message)
reg <- lapply(split(TRY, VARIABLE2), function(X){lm(X2 ~ X3, data=X)})
lapply(reg, summary)
Which produces the following:
$`1`
Call:
lm(formula = X2 ~ X3, data = X)
Residuals:
Min
2012 Mar 24
1
Solving the equation using uniroot
Hello all,
I was going to solve (n-m)! * (n-k)! = 0.5 *n! * (n-m-k)!
for m when values of n and k are provided
n1<-c(10,13,18,30,60,100,500) # values of n
kx<-seq(1,7,1); # values of k
slv2<-lapply(n1,function(n){
slv1<-lapply(kx,function(k){
lhs<-function(m)
{
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]
2011 Feb 11
3
How can we make a vector call a function element-wise efficiently?
Hello
I have a time-comsuming program which need to simplify, I have tested the annotated program as follow:
> #define function which will be call
> calsta <- function(c, n=100000)
+ {
+ i <- seq(from=0, length=c)
+ logx <- lchoose(NT-n, CT-i) + lchoose(n, i)
+ logmax <- max(logx)
+ logmax + log(sum(exp(logx - logmax)))
+ }
> CT=6000 #assignment to CT
>
2004 Sep 30
1
Vectorising and loop (was Re: optim "a log-likelihood function")
>From: Sundar Dorai-Raj <sundar.dorai-raj at PDF.COM>
>Reply-To: sundar.dorai-raj at PDF.COM
>To: Zhen Pang <nusbj at hotmail.com>
>CC: r-help at stat.math.ethz.ch
>Subject: Vectorising and loop (was Re: [R] optim "a log-likelihood
>function")
>Date: Wed, 29 Sep 2004 18:21:17 -0700
>
>
>
>Zhen Pang wrote:
>
>>
>>I also use
2011 Jan 07
4
how to calculate this natural logarithm
Hello
I want to calculate natural logarithm of sum of combinations as follow: (R code)
{
com_sum=choose(2000000,482)*choose(1000000,118)+choose(2000000,483)*choose(1000000,117)+...+choose(2000000,i)*choose(1000000,600-i)+...+choose(2000000,600)*choose(1000000,0) #calculate the sum
result=log(com_sum) #calculate the log of the sum
}
But
2008 Feb 27
1
dhyper, phyper (PR#10853)
Aloha all,
I know too little about what I'm about to write and hope I'm not
wasting your time.
For a class I'm teaching in archaeological data analysis, I'm trying
to put together a routine that calculates the so-called Petersen
index and, especially, confidence intervals for the index. This was
introduced to archaeologists by N.R.J. Fieller and A. Turner in an
article
2006 Jul 22
1
Why the contrain does not work for selecting a particular range of data?
Dear:
Continuing the issue of 'ifelse'! I selecting the data whose 'x2'=1 for maximizing likelihood. I used two way to do this but the results are different.
1.Way one I use the data for x2=1 and run the program. It works for me. Tthe program is described as below:
function (parameters,y1,x11)
{
p<-parameters[1]
alpha1<-parameters[2]
beta1<-parameters[3]
2001 Dec 04
3
factorial() not here (PR#1194)
Version 1.3.1 (2001-08-31)
factorial() is not in R. It is in S-Plus with the definition
factorial <- function(n) gamma(n + 1)
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not
2009 Jul 30
3
Looping through R objects with $ operator and tags
Hi all,
Suppose I want to set the values in a column to the log of the values
of another column like so:
object$LogDist <- log10(object$Distance)
How do I loop through the objects if I have object1, object2, etc to
perform this function?
object1$LogDist <- log10(object1$Distance)
object2$LogDist <- log10(object2$Distance)
object3$LogDist <- log10(object3$Distance)
I was trying to
2012 Jan 13
1
Brillouin index
Dear colleagues.
I wonder if anybody knows about a procedure in R to calculate the Brillouin Diversity index.
I searched the net but did not find anything about it.
Thanks a lot for any help
Best, Philipp
***************************************************
Prof. Dr. Philipp Fischer
Head of AWI Center for Scientific Diving & Dept. In situ Ecology
Section Shelf Sea Systems
2008 Feb 18
2
Huge number
Hi,
I'm trying to calculate p-value to findout definitely expressed genes
compare A to B situation.
I got this data(this is a part of data) from whole organism , and each
number means each expression values (that means, we could think 'a' gene
is 13 in A situation, and it turns 30 in B situation)
To findout probability, I'm going to use Audic - Claverie Method. ( The
significance
2011 Feb 12
1
how to improve the precison of this calculation?
Hello
T
I want to order some calculation "result", there will be lots of "result" that need to calculate and order
PS: the "result" is just a intermediate varible and ordering them is the very aim
# problem:
# For fixed NT and CT, and some pair (c,n). order the pair by corresponding result
# c and n are both random variable
CT<-6000 #assignment to CT
2011 Feb 01
6
help
PLEASE HELP
I actually want to do the following:
a[j] = (1/(j!))*Π (i-1-d), j = 500, Π means product i = 1 to
j
Yet, j! will stop at 170 and Π (i-1-d) at 172; so, a[j] will
not exceed 170.
I would like to have at least 200 a[j].
WHAT SHOULD I DO?
PLEASE SEE MY CODE FOR DETAIL!!
####################################################
R CODE:
2006 Nov 15
1
OPTIM--non finite finite different [13]
Dear All:
I used optim() to minimise the loglikelihood function for fitting data to negative binomial distribution. But there initial value of log-likelihood and iteration 10 value are reasonable. for example:
initial value 1451657.994524
iter 10 value 47297.534905
iter 20 value -623478636.8236478
Then the iter 20 vlaue suddelnly changes to a negative value and in the end the error mesage is
2020 Jan 14
4
[R] choose(n, k) as n approaches k
OK, I see what you mean. But in those cases, we don't get the catastrophic failures from the
if (k < 0) return 0.;
if (k == 0) return 1.;
/* else: k >= 1 */
part, because at that point k is sure to be integer, possibly after rounding.
It is when n-k is approximately but not exactly zero and we should return 1, that we either return 0 (negative case) or n
2008 Jul 09
1
Loglikelihood for x factorial?
Hi Rers,
I have a silly question. I don't know how to express the loglikelihood
function of
1/(x!) where x=x1,x2,....xn in R.
Could anyone give me a hint?
Thank you in advance.
Chunhao Tu
2020 Jan 14
2
[R] choose(n, k) as n approaches k
> On 14 Jan 2020, at 16:21 , Duncan Murdoch <murdoch.duncan at gmail.com> wrote:
>
> On 14/01/2020 10:07 a.m., peter dalgaard wrote:
>> Yep, that looks wrong (probably want to continue discussion over on R-devel)
>> I think the culprit is here (in src/nmath/choose.c)
>> if (k < k_small_max) {
>> int j;
>> if(n-k < k
2008 Aug 12
2
Maximum likelihood estimation
Hello,
I am struggling for some time now to estimate AR(1) process for commodity price time series. I did it in STATA but cannot get a result in R.
The equation I want to estimate is: p(t)=a+b*p(t-1)+error
Using STATA I get 0.92 for a, and 0.73 for b.
Code that I use in R is:
p<-matrix(data$p) # price at time t
lp<-cbind(1,data$lp) # price at time t-1