Displaying 20 results from an estimated 400 matches similar to: "speeding up likelihood computation"
2007 Apr 18
3
Problems in programming a simple likelihood
As part of carrying out a complicated maximum likelihood estimation, I
am trying to learn to program likelihoods in R. I started with a simple
probit model but am unable to get the code to work. Any help or
suggestions are most welcome. I give my code below:
************************************
mlogl <- function(mu, y, X) {
n <- nrow(X)
zeta <- X%*%mu
llik <- 0
for (i in 1:n) {
if
2010 Nov 16
2
Integrating functions / vector arithmetic
Hello,
I was trying to build some functions which I would like to integrate over an
interval using the function 'integrate' from the 'stats' package. As an
example, please consider the function
h(u)=sin(pi*u) + sqrt(2)*sin(pi*2*u) + sqrt(3)*sin(pi*3*u) + 2*sin(pi*4*u)
Two alternative ways to 'build' this function are as in f and g below:
coeff<-sqrt(1:4)
2009 Dec 10
2
Assigning variables into an environment.
I am working with a somewhat complicated structure in which
I need to deal with a function that takes ``basic'' arguments
and also depends on a number of parameters which change depending
on circumstances.
I thought that a sexy way of dealing with this would be to assign
the parameters as objects in the environment of the function in
question.
The following toy example gives a bit of the
2017 Aug 18
1
A question about for loop
Dear R users,
I have the following codes:
zeta <- rep(1,8)
n <- 7
for (i in 1:2){
beta <- zeta[1:n+(i-1)*(n+1)]
print(beta)
parm <- zeta[i*(n+1)]
print(parm)
}
###################
The output is as follows:
[1] 1 1 1 1 1 1 1
[1] 1
[1] NA NA NA NA NA NA NA
[1] NA
#######################
The outcome I want to get is:
[1] 1 1 1 1 1 1 1
[1] 1
[1] 1 1 1 1 1 1 1
[1] 1
How could I get the
2003 Oct 11
1
boot statictic fn for dual estimation of 2 stats?
Hi,
I am trying to use boot() to refit an ordinal logit (polr in MASS) model.
(A very basic bootstrap which samples from the data frame without
replacement and updates the model.)
I need to extract two statistics per run (the coefficients and zeta) and I
tried concatenating them into a single vector after fitting, but I get the
following error:
Error in "[<-"(*tmp*, r, ,
2010 Apr 22
1
nv20tcl and renouveau questions
First some data errors I get with both nv20 exa and nv20 dri/mesa.
1.
RT_FORMAT
LINEAR + X8R8G8B8
Ch 1/5 Class 0x0597 Mthd 0x0208 Data 0x00800080:0x00000105
Ch 1/5 Class 0x0597 Mthd 0x0208 Data 0x01000100:0x00000105
LINEAR + A8R8G8B8
Ch 1/5 Class 0x0597 Mthd 0x0208 Data 0x01000100:0x00000108
Ch 1/5 Class 0x0597 Mthd 0x0208 Data 0x00800080:0x00000108
The only value I found in renouveau dump
2010 Jul 22
1
, how to express bar(zeta) in main title in boxplot
Hi everyone, I am plotting a boxplot with main title as main =
bquote(paste(.(ts.ind[s]), ": ", bar(zeta), " Boxplot from 2001 to 2009", sep = "")) but it doesn't work. The program said they cannot find the function "bar". Does anyone know how to do it correctly? Thanks.
tin
[[alternative HTML version deleted]]
2009 Jun 17
2
Difference beetwen element in the same column
Hi, i have this file
pressure,k,eps,zeta,f,velocity:0,velocity:1,velocity:2,vtkValidPointMask,Point
Coordinates:0,Point Coordinates:1,Point Coordinates:2,vtkOriginalIndices
0.150545,0.000575811,0.0231277,0.000339049,-0.0193008,0.00318629,-6.24066e-07,5.39599e-05,^A,7,0,0,0
0.150546,0.000782719,0.0226157,0.000497957,-0.0192084,0.00367781,5.09813e-06,5.90689e-05,^A,7,0.0003035,0.000225,1
2009 Apr 04
2
threshold distribution
Dear ALL
I have a list of data below
0.80010 0.72299 0.69893 0.99597 0.89200 0.69312 0.73613 1.13559
0.85009 0.85804 0.73324 1.04826 0.84002
1.76330 0.71980 0.89416 0.89450 0.98670 0.83571 0.73833 0.66549
0.93641 0.80418 0.95285 0.76876 0.82588
1.09394 1.00195 1.14976 0.80008 1.11947 1.09484 0.81494 0.68696
0.82364 0.84390 0.71402 0.80293 1.02873
all of them are ninty.
Nowaday, i try to find a
2010 Nov 03
2
bugs and misfeatures in polr(MASS).... fixed!
In polr.R the (several) functions gmin and fmin contain the code
> theta <- beta[pc + 1L:q]
> gamm <- c(-100, cumsum(c(theta[1L], exp(theta[-1L]))), 100)
That's bad. There's no reason to suppose beta[pc+1L] is larger than
-100 or that the cumulative sum is smaller than 100. For practical
datasets those assumptions are frequently violated, causing the
2010 Jan 04
1
polygamma or Hurwitz zeta function
Hi,
Is there any R library that is capable of handling polygamma function
(Hurwitz zeta function also works)? I am aware of digamma(0 and trigamma(),
but could not find more advanced versions.
I'd appreciate any help.
Hakan Demirtas
2007 Feb 08
1
Zeta and Zipf distribution
Dear R user,
I want to estimate the parameter of ZETA or/and ZIPF distributions
using R, given a series of integer values. Do you know a package
(similar to MASS) or a function (similar to fitdistr) I can use to
estimate the parameter of these distributions using MLE method?
Otherwise do you know a function (which use MLE method to estimate
distribution parameters) that allow me to specify a
2004 Aug 06
5
Memory leak in denoiser + a few questions
Hello
The st->zeta pointer isn't freed in the speex_preprocess_state_destroy()
function of the preprocess.c file (alloced in line 167). It's in Speex 1.1.4
by the way.
I'm trying to make the denoiser work with my application and has got
reasonable noise reduction after applying the denoiser. I, however, haven't
been able to find any information of what the purpose of
2015 Oct 06
19
[Bug 92306] New: GL Excess demo renders incorrectly on nv43
https://bugs.freedesktop.org/show_bug.cgi?id=92306
Bug ID: 92306
Summary: GL Excess demo renders incorrectly on nv43
Product: Mesa
Version: git
Hardware: x86 (IA32)
OS: Linux (All)
Status: NEW
Severity: normal
Priority: medium
Component: Drivers/DRI/nouveau
Assignee: nouveau
2004 Jun 30
1
interval regression
Hi,
does anyone have a quick answer to the question of how to carry out
interval regression in R. I have found "ordered logit" and "ordered
probit" as well as multinomial logit etc. The thing is, though, that I
want to apply logit/probit to interval-coded data and I know the cell
limits which are used to turn the quantitative response into an ordered
factor. Hence, it does
2013 May 02
0
How does dsgh do the standardization?
Hi,
I try to understand how the generalized hyperbolic distribution is
standardized. One reference is the rugarch vignette, page 16-18:
http://cran.r-project.org/web/packages/rugarch/vignettes/Introduction_to_the_rugarch_package.pdf
I looked at the code of the dsgh function in the fBasics package:
> dsgh
function (x, zeta = 1, rho = 0, lambda = 1, log = FALSE)
{
if (length(zeta) == 3) {
2008 May 08
2
[LLVMdev] VirtRegMap Error
I just updated from upstream llvm as of about last Thursday and I'm
getting a segfault in VirtRegMap::RemoveMachineInstrFromMaps.
It seems that the particular instruction being removed happens
to reference an object at stack slot 4. The first spilled register is
assigned stack slot 6 so LowSpillSlot == 6. Then, when we try to
erase from SpillSlotToUsesMap, we index with a negative number.
2007 Feb 07
6
setting a number of values to NA over a data.frame.
This is probably a simple problem but I don't see a
solution.
I have a data.frame with a number of columns where I
would like 0 <- NA
thus I have df1[,144:157] <- NA if df1[, 144: 157] ==0
and df1[, 190:198] <- NA if df1[, 190:198] ==0
but I cannot figure out a way do this.
cata <- c( 1,1,6,1,1,NA)
catb <- c( 1,2,3,4,5,6)
doga <- c(3,5,3,6,4, 0)
dogb <- c(2,4,6,8,10,
2007 Oct 18
1
R-graphics printing greeks
I have tried to print a table of greek alphabet names and symbols
without success. I can print one character at a time but can't seem to
find a way to automate an entire list of the symbols. Some of the code I
have tried is below. I have searched on help, worked the examples in the
December 2002 R Help Desk article and plotmath but have not been able
to find a way to accomplish the
2004 Dec 09
3
surf.ls
Hello,
I am looking into description of surf.ls(spatial)
and see under value $beta - the coefficients.
When I use polynomial of degree 2 to fit surface
I expect to get 4 coefficients:
z = a_1 x^2 + a_2 xy + a_3 y^2 + a_4
What do beta really stand for and why do I get
$beta vector of length 6?
Thakns,
Mark