Displaying 20 results from an estimated 1000 matches similar to: "problem with convergence in mle2/optim function"
2012 Sep 27
0
problems with mle2 convergence and with writing gradient function
Dear R help,
I am trying solve an MLE convergence problem: I would like to estimate
four parameters, p1, p2, mu1, mu2, which relate to the probabilities,
P1, P2, P3, of a multinomial (trinomial) distribution. I am using the
mle2() function and feeding it a time series dataset composed of four
columns: time point, number of successes in category 1, number of
successes in category 2, and
2012 Oct 11
2
model selection with spg and AIC (or, convert list to fitted model object)
Dear R Help,
I have two nested negative log-likelihood functions that I am optimizing
with the spg function [BB package]. I would like to perform model
selection on these two objective functions using AIC (and possibly
anova() too). However, the spg() function returns a list and I need a
fitted model object for AIC(), ICtab() [bbmle package], or anova().
How can I perform AIC-based model
2007 Oct 23
1
How to avoid the NaN errors in dnbinom?
Hi, The code below is giving me this error message:
Error in while (err > eps) { : missing value where TRUE/FALSE needed
In addition: Warning messages:
1: In dnbinom(x, size, prob, log) : NaNs produced
2: In dnbinom(x, size, prob, log) : NaNs produced
I know from the help files that for dnbinom "Invalid size or prob will
result in return value NaN, with a warning", but I am not able
2006 May 21
2
nls & fitting
Dear All,
I may look ridiculous, but I am puzzled at the behavior of the nls with
a fitting I am currently dealing with.
My data are:
x N
1 346.4102 145.428256
2 447.2136 169.530634
3 570.0877 144.081627
4 721.1103 106.363316
5 894.4272 130.390552
6 1264.9111 36.727069
7 1788.8544 52.848587
8 2449.4897 25.128742
9 3464.1016 7.531766
10 4472.1360 8.827367
11
2008 Feb 15
1
Questions about EM algorithm
Dear all:
Assume I have 3 distributions, x1, x2, and x3.
x1 ~ normal(mu1, sd1)
x2 ~ normal(mu2, sd2)
x3 ~ normal(mu3, sd3)
y1 = x1 + x2
y2 = x1 + x3
Now that the data I can observed is only y1 and y2. It is
easy to estimate (mu1+m2), (mu1+mu3), (sd1^2+sd2^2) and
(sd1^2+sd3^2) by EM algorithm since
y1 ~ normal(mu1+mu2, sqrt(sd1^2+sd2^2)) and
y2 ~ normal(mu1+mu3, sqrt(sd1^2+sd3^2))
However, I want
2007 Mar 06
2
Estimating parameters of 2 phase Coxian using optim
Hi,
My name is Laura. I'm a PhD student at Queen's University Belfast and have
just started learning R. I was wondering if somebody could help me to see
where I am going wrong in my code for estimating the parameters [mu1, mu2,
lambda1] of a 2-phase Coxian Distribution.
cox2.lik<-function(theta, y){
mu1<-theta[1]
mu2<-theta[2]
lambda1<-theta[3]
2013 Feb 01
2
How does this function print, why is n1 which equals 1 printed as 2?
Windows 7, R 2.12.1
Colleagues,
I am trying to understand the n.for.2means function. The code below is a copy of the function (renamed to n.for.2means.js). I have inserted a single line of code towards the bottom of the function which uses the cat function to print the value of n1. You will note the value (preceded by stars) is printed as 1.
The function (1) prints a lot of output without any
2010 Jun 13
1
using latticeExtra plotting confidence intervals
I am wanting to plot a 95% confidence band using segplot, yet I am wanting
to have groups. For example if I have males and females, and then I have
them in different races, I want the racial groups in different panels. I
have this minor code, completely made up but gets at what I am wanting, 4
random samples and 4 samples of confidence, I know how to get A & B into one
panel and C&D in to
2005 Nov 09
2
About: Error in FUN(X[[1]], ...) : symbol print-name too long
Hi,
I??m trying to use the Win2BUGS package from R and I have a similar problem
that reurns with the message:
Error in FUN(X[[1]], ...) : symbol print-name too long
But, there is no stray ` character in the file ( Sugestions given by: Duncan
Temple Lang <duncan>
Date: Mon, 26 Sep 2005 07:31:08 -0700 )
The progam in R is:
library(R2WinBUGS)
library(rbugs)
dat <-
2006 Jun 07
2
help with combination problem
hello:
I have 3 data.frame objects.
First df object:
Of dim (149,31). Columns 2:31 are marked as T1..T14
and N1..N16.
Name T1 T2 N1 T3 N2 N3 N4 T4
mu1 10 10 9 10 9 9 8 10
mu2 11 11 9 11 9 9 9 11
...
muN 12 12 9 11 9 9 8 12
Second df object:
of Dim (50000,31). Columns 2:31 are maked as T1...T14
and N1..N16.
2008 Apr 05
2
How to improve the "OPTIM" results
Dear R users,
I used to "OPTIM" to minimize the obj. function below. Even though I used
the true parameter values as initial values, the results are not very good.
How could I improve my results? Any suggestion will be greatly appreciated.
Regards,
Kathryn Lord
#------------------------------------------------------------------------------------------
x = c(0.35938587,
2008 Apr 05
2
How to improve the "OPTIM" results
Dear R users,
I used to "OPTIM" to minimize the obj. function below. Even though I used
the true parameter values as initial values, the results are not very good.
How could I improve my results? Any suggestion will be greatly appreciated.
Regards,
Kathryn Lord
#------------------------------------------------------------------------------------------
x = c(0.35938587,
2003 Nov 20
2
reading data rows
I have problems reading a file with more than one row
to carry out mathematical calculations
I have a a file of the form
mu1 mu2 alpha beta Wsigma sigmaA b r
25 15 .05 .05 22 3 .3 .5
30 20 .1 .2 22 .3 .3 .5
I intend to read one row , carry out the calculations
and then the next row with which I intend to do the
same calculations.
I do the following.
2009 Oct 31
1
Help me improving my code
Hi,
I am new to R. My problem is with the ordered logistic model. Here is my
question:
Generate an order discrete variable using the variable
wrwage1 = wages in first full calendar quarter after benefit application
in the following way:
*
wage*1*Ordered *=
1 *if*0 *· wrwage*1 *< *1000
2 *if*1000 *· wrwage*1 *< *2000
3 *if*2000 *· wrwage*1 *< *3000
4 *if*3000 *· wrwage*1 *<
2008 Mar 15
2
Please find the error in my code
hello everybody
I use the following code for my programming & it runs with the error as specified below.Any help that would disolve the error will be highly appreciated.
Thanks in advance
my code looks like this
#### R programme for simulating the power of the two sample t test vs various
#### non-parametric alternatives
sim.size <- 200
sample.size <- 10
set.seed(231)
mu1 <- 0
delta
2010 Jul 18
2
loop troubles
Hi all, I appreciate the help this list has given me before. I have a
question which has been perplexing me. I have been working on doing a
Bayesian calculating inserting studies sequentially after using a
non-informative prior to get a meta-analysis type result. I created a
function using three iterations of this, my code is below. I insert prior
mean and precision (I add precision manually
2003 Jul 06
1
Conditional Distribution of MVN variates
Hi Folks,
Given k RVs with MVN distribution N(mu,S) (S a kxk covariance matrix),
let (w.l.o.g.) X1 denote the first r of them, and X2 the last (k-r).
Likewise, let mu1 and mu2 denote their respective expectations.
Then, of course, the expectation of X2 given X1=x1 is
mu2 + S21*inv(S22)*(x1 - mu1)
and the covariance matrix of X2 given X1=x2 is
S22 - S21*inv(X11)*S12
where Sij is the
2007 Jan 01
4
Help with filled.contour()
The following plot is a first approximation to what I need:
***********************************
mu1 <- 0
mu2 <- 5
s <- 1
x <- seq(-2.5, 7.5, length = 41)
y <- seq(-2.5, 2.5, length = 41)
f <- function(x,y){
term1 <- 1/(2*pi*sqrt(s*s))
term2 <- -1/2
term3 <- (x - mu1)^2/s
term4 <- (y - mu1)^2/s
term5 <- (x - mu2)^2/s
term1*(.5 * exp(term2*(term3 + term4)) + .5 *
2024 Aug 09
3
If loop
Can someone help me with the if loop below? In the subroutine, I
initialize all of (joint12,marg1,marg2,cond12,cond21) as FALSE, and call
with only one of them being TRUE:
,...,joint12=FALSE,marg1=FALSE,marg2=FALSE,cond12=FALSE,cond21=FALSE,,,,
joint12 seems to always kick in, even though I call with, e.g., marg1
being TRUE and everything else being FALSE. My attempts with if... else
if were
2008 Jul 28
1
Mixed model question.
I continue to struggle with mixed models. The square zero version
of the problem that I am trying to deal with is as follows:
A number (240) of students are measured (tested; for reading
comprehension)
on 6 separate occasions. Initially (square zero) I want to treat the
test time as a factor (with 6 levels). The students are of course
``random effects''. Later I want to look at