Displaying 20 results from an estimated 1000 matches similar to: "Likelihood optimization numerically"
2006 Oct 15
1
gamma distribution don't allow negative value in GLMs?
Dear friends,
when i use glm() to fit my data, i use
glm(formula = snail ~ vegtype + mhveg + humidity + elevation + soiltem, *family
= Gamma(link = inverse),* data =a,))
It shows: error in eval(expr, envir, enclos) : *gamma distribution don't
allow negative value*.
But i use
result<-glm(formula = snail ~ vegtype + mhveg + humidity + elevation +
soiltem, family = poisson, data =a) #this
2010 Apr 16
2
managing data and removing lines
Hi,
I am very new to R and I've been trying to work through the R book to gain a
better idea of the code (which is also completely new to me).
Initially I imputed my data from a text file and that seemed to work ok, but
I'm trying to examine linear relationships between gdist and gair, gdist and
gsub, m6dist and m6air, etc.
This didn't work and I think it might have something to do
2010 Sep 09
5
Help on simple problem with optim
Dear all,
I ran into problems with the function "optim" when I tried to do an mle estimation of a simple lognormal regression. Some warning message poped up saying NANs have been produced in the optimization process. But I could not figure out which part of my code has caused this. I wonder if anybody would help. The code is in the following and the data is in the attachment.
da <-
2011 May 20
1
Factors to Columns
> str(data)
'data.frame': 250 obs. of 3 variables:
$ student: chr "A" "B" "C" "D" ...
$ data : num 20.2 20.4 22.5 22.1 23.3 ...
$ param : Factor w/ 4 levels "AGE","SCHOOL",..: 1 1 1 1 1 1 1 1 1 1
Hi , i would like to split the dataframe so that each level of param is
a column
At the end it should look like
2005 Mar 02
1
Warning: number of items to replace is not a multiple of replacement length
I feel like a complete dolt, as I know this question has been asked by
others on a fairly regular basis, but I'm going in circles trying to get
the following to work:
id.prob<-function (tt)
{
library(mvtnorm)
#============================
Makeham<-function(tt)
{
a2=0.030386513
a3=0.006688287
b3=0.039047537
t<-tt-20
h.t<-a2+a3*exp(b3*t)
S.t<-exp(-a2*t+a3/b3*(1-exp(b3*t)))
2003 Jul 09
2
A problem with using the "outer" function
Hi:
I am using R 1.7.0 on Windows. I am having trouble getting "outer" to
work on one of my functions. Here is a simple example illustrating my
problem:
> b1 <- c(1.2,2.3)
> b2 <- c(0.5,0.6)
> x <- c(3e+01, 1e+02, 3e+02, 5e+02, 1e+03, 1e+04, 1e+05, 1e+06)
> y <- c(2,4,2,5,2,3,1,1)
> n <- c(5,8,3,6,2,3,1,1)
> outer(b1,b2,FUN=bpllkd,x,y,n)
2007 May 24
3
Problem with numerical integration and optimization with BFGS
Hi R users,
I have a couple of questions about some problems that I am facing with
regard to numerical integration and optimization of likelihood
functions. Let me provide a little background information: I am trying
to do maximum likelihood estimation of an econometric model that I have
developed recently. I estimate the parameters of the model using the
monthly US unemployment rate series
2012 Nov 12
1
Invalid 'times' argument three-category ordered probit with maximum likelihood
Hello,
First time poster here so let me know if you need any more information. I am
trying to run an ordered probit with maximum likelihood model in R with a
very simple model (model <- econ3 ~ partyid). Everything looks ok until i
try to run the optim() command and that's when I get " Error in rep(1,
nrow(x)) : invalid 'times' argument". I had to adapt the code from a 4
2007 Feb 19
1
need help in reading TOMS observed ASCII data file
Hello R Users,
I am new to R.
I have two data sets i) TOMS aerosol optical depth(AOD) and ii) TOMS
ozone(O3).
>
> AOD data is on 1x1 grid and O3 data is on 5x5 grid.
>
> First I want to read AOD and O3 as it is and then I want to regrid AOD on
> 5x5 grid as O3.
>
> Reading is first problem.
>
> FIRST PROBLEM READING AOD:
>
> AOD data is in following format:
>
2007 Aug 20
1
Ask for functions to obtain partial R-square (squared partial correlation coefficients)
The partial R-square (or coefficient of partial determination, or
squared partial correlation coefficients) measures the marginal
contribution of one explanatory variable when all others are already
included in multiple linear regression model.
The following link has very clear explanations on partial and
semi-partial correlation:
http://www.psy.jhu.edu/~ashelton/courses/stats315/week2.pdf
In
2007 Oct 14
1
Dendrogram
? stato filtrato un testo allegato il cui set di caratteri non era
indicato...
Nome: non disponibile
Url: https://stat.ethz.ch/pipermail/r-help/attachments/20071014/8b7a455c/attachment.pl
2005 Mar 08
1
coefficient of partial determination...partial r square [ redux]
If I'm not mistaken, partial R-squared is the R^2 of the quantities plotted
in a partial residual plot, so you can base the computation on that. Prof.
Fox's `car' package on CRAN has a function for creating those plots, but you
need to figure out the way to extract the quantities being plotted.
[In any case, the basic tools for doing such computations are all in R, and
it
2012 Oct 02
2
Questions on converting to ConfBridge
I'm looking at what would be involved in converting from MeetMe to
ConfBridge and there seems to be a lot of missing administrative things,
but I hope I'm just missing it. We all know about the missing realtime
linkage. That's a major nuisance, but can be worked around.
More serious is that the CLI command to display users in a ConfBridge
don't show the caller ID information, so
2006 Apr 07
1
Aggregating an its series
I'm using a very long irregular time-series of air temperature and
relative humidity of this kind (this is an extract only)
its.format("%
Y%d%m %X)
> base
T H
20020601
12.00.00 27.1 47
20020601 15.00.00 29.1 39
20020601 18.00.00 27.4 39
20020601 21.00.00 24.0 40
20020602 0.00.00 22.0 73
20020602 3.00.00
19.2 49
20020602 6.00.00 19.5 74
20020602
2006 Jan 06
7
Multiplication (PR#8466)
hi - in version 2.1 the command
>-2^2
gives
-4
as the answer. (-2)^2 is evaluated correctly.
Cheers,
George Casella
--
George Casella Phone: (352) 392-1941 Ext. 204
Distinguished Professor and Chair Cell: (352) 682-7210
Department of Statistics Fax: (352) 392-5175
University of Florida Email: casella at stat.ufl.edu
P.O. Box 118545
Gainesville, FL
2006 Jan 06
7
Multiplication (PR#8466)
hi - in version 2.1 the command
>-2^2
gives
-4
as the answer. (-2)^2 is evaluated correctly.
Cheers,
George Casella
--
George Casella Phone: (352) 392-1941 Ext. 204
Distinguished Professor and Chair Cell: (352) 682-7210
Department of Statistics Fax: (352) 392-5175
University of Florida Email: casella at stat.ufl.edu
P.O. Box 118545
Gainesville, FL
2010 Sep 27
1
Split-split plot design with aov function in R
*Hello,
I'm new to R and trying to do Split Split Plot Design analysis with aov
function in R. Sharing any worked example and suggestion will be highly
appreciated. Thanks
Regards!
*
--
*
Muhammad Yaseen
*
[[alternative HTML version deleted]]
2010 Sep 14
1
NA confusion (length question)
Hi folks,
I am running a very simple regression using
mylm <- lm(mass ~ tarsus, na.action=na.exclude)
I would like the use the residuals from this analysis for more
regression but I'm running into a snag when I try
cbind(mylm$residuals, mydata) # where my data is the original data set
The error tells me that it cannot use cbind because the length of
mylm$residuals is
2005 Nov 07
2
how to export density_function output?
Dear all,
quite a naive question: I have a data frame and I computed "the kernel
density estimate" with density on each column.
Now I'd like to export in a txt file the density function output for each
column, but, when if I use write.table, I get a message "Error in
as.data.frame.default(x[[i]], optional = TRUE) : can't coerce class
"density" into a
2007 Apr 20
2
sorting data in R
hello,
I'd like know how to sort a data frame in R for example how I should do to sort by Catholic with swiss data frame like below
thanks
Fertility Agriculture Examination Education Catholic Infant.Mortality
Courtelary 80.2 17.0 15 12 9.96 22.2
Delemont 83.1 45.1 6 9 84.84 22.2