Displaying 13 results from an estimated 13 matches for "realston".
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ralston
2008 Nov 03
1
IWLS vs direct ML estimation
Hi,
I am thinking about IWLS vs ML estimation. When I use glm() for a
2-parameter distribution (e.g., Weibull), I can otain the MLE of scale
parameter given shape parameter through IWLS. Because this scale parameter
usually converges to the MLE.
In this point, I am wondering:
i) can you say that the direct MLE, which is obtained by maximizing a
likelihood function, is equalvant to the indirect
2008 Sep 29
3
count data with a specific range
Hi there,
The data is
data<-c(2,6,13,26,19,25,18,11,22,25)
I want to count data for these rages:
[0~10]:
[11~20]:
[21-30]:
Is anyone can help me?
Thank you in advance
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2009 Jul 29
3
how to skip a numeric column for averaging other columns?
Data has the first row for variable name and the first column for sample
name. I want to take "Log" for all data, but how to compute without the
first column for sample name.
That is,
column 1: sample ID
column 2-10: data
I want to find an average on each column (2-10)
> apply(raw_data,2,mean)
Error in Math.data.frame(list(sample_id = c(1L, 2L, 3L, 4L, 5L, 6L, 7L, :
2008 Nov 01
2
calculation for standard normal cumulative distribution
Is there anyone knowing a function or way for standard normal cumulative
distribution?
?(z=-0.1)=?
also
?(z=?)=0.025
Thank you,
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2008 Oct 15
0
R-help Digest, Vol 67, Issue 31
...nchester.ac.uk>
Fax-to-email: +44 (0)870 094 0861
Date: 29-Sep-08 Time: 22:33:33
------------------------------ XFMail ------------------------------
------------------------------
Message: 76
Date: Mon, 29 Sep 2008 14:41:44 -0700 (PDT)
From: sandsky <realstone at hotmail.com>
Subject: [R] count data with a specific range
To: r-help at r-project.org
Message-ID: <19732290.post at talk.nabble.com>
Content-Type: text/plain; charset=us-ascii
Hi there,
The data is
data<-c(2,6,13,26,19,25,18,11,22,25)
I want to count data for these rages:
[0...
2009 Nov 23
1
Re moving rows which do not satisfy a condition
Hello,
Considering 5 points in X-Y plain. Data is a 5*2 matrix (5 rows for samples
& 2 columns for X and Y)
With a distance from the origin, if a distance < 7, remove the row from the
Data.
After calculating the distance for each point, I can't forward because of
this "Removing" problem.
Anyone can help me?
Data=matrix(1:10,5,2)
a=rep(0,5);
b=rep(0,5);
for (i in
2010 Mar 25
1
how to deal with vector[0]?
Hi,
I have a vector with 4 elements, e.g., tau_i=c(100,200,300,400), but
potentially tau_i[0]=0. In a "for" loop,
tau_i=c(100,200,300,400)
m=4
tau_i[0]=0 # <------- ?
P_i=1
for(i in 2:m)
{
P_i = P_i*(tau_i[i-1]-tau_i[i-2])
}
Error in P_i = P_i * (tau_i[k - 1] - tau_i[k - 2]):
replacement has length zero
Unfortunately, I can add this potential element into
2010 Mar 29
1
generating samples by Monte Carlo
Hello Dear,
I am trying to generate samples by using Monte Carlo simulation. For
example,
1000 samples, Exponential distribution (f(x), lambda=0.0005, 0<=x<=360)
Is there any package for Monte Carlo or just use random sample generation
function?
Many thank you for your help in advance,
Jin
--
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2008 Sep 11
0
Loop for the convergence of shape parameter
Hello,
The likelihood includes two parameters to be estimated: lambda
(=beta0+beta1*x) and alpha. The algorithm for the estimation is as
following:
1) with alpha=0, estimate lambda (estimate beta0 and beta1 via GLM)
2) with lambda, estimate alpha via ML estimation
3) with updataed alpha, replicate 1) and 2) until alpha is converged to a
value
I coded 1) and 2) (it works), but faced some
2010 Apr 20
1
3D surface plot with wireframe or persp?
Hello Dear,
I have a function, like z=f(x,y), and try a surface plot with this function.
But, on the reference of "wireframe" requires data option, so I generated x
and y, and computed z with them. But, still I have a problem to draw a
surface plot. The code and errors are
##################################################
mle_beta0=64.43707;
mle_beta1=-24365.16;
# generating for
2008 Sep 09
1
Genmod in SAS vs. glm in R
Hello,
I have different results from these two softwares for a simple binomial GLM
problem.
>From Genmod in SAS: LogLikelihood=-4.75, coeff(intercept)=-3.59,
coeff(x)=0.95
>From glm in R: LogLikelihood=-0.94, coeff(intercept)=-3.99, coeff(x)=1.36
Is there anyone tell me what I did wrong?
Here are the code and results,
1) SAS Genmod:
% r: # of failure
% k: size of a risk set
data
2008 Sep 12
1
Error in "[<-"(`*tmp*`, i, value = numeric(0)) :
I use "while" loop but it produces an errro. I have no idea about this.
Error in "[<-"(`*tmp*`, i, value = numeric(0)) :
nothing to replace with
The problem description is
The likelihood includes two parameters to be estimated: lambda
(=beta0+beta1*x) and alpha. The algorithm for the estimation is as
following:
1) with alpha=0, estimate lambda (estimate beta0
2008 Sep 19
2
Error: function cannot be evaluated at initial parameters
I have an error for a simple optimization problem. Is there anyone knowing
about this error?
lambda1=-9
lambda2=-6
L<-function(a){
s2i2f<-(exp(-lambda1*(250^a)-lambda2*(275^a-250^a))
-exp(-lambda1*(250^a)-lambda2*(300^a-250^a)))
logl<-log(s2i2f)
return(-logl)}
optim(1,L)
Error in optim(1, L) : function cannot be evaluated at initial parameters
Thank you in advance
--
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