Displaying 20 results from an estimated 200 matches similar to: "weighted nls and confidence intervals"
2007 Aug 31
0
non-linear fitting (nls) and confidence limits
dear list members,
I apologize in advance for posting a second time, but probably after one
week chances are, the first try went down the sink..
my question concerns computation of confidence intervals in nonlinear fits
with `nls' when weigthing the fit. the seemingly correct procedure does not
work as expected, as is detailed in my original post below.
any remarks appreciated.
greetings
2007 Sep 25
0
non-linear fitting (nls) and confidence limits
dear list members,
my question concerns computation of confidence intervals in nonlinear
fits with `nls' when weigthing the fit. the seemingly correct procedure
does not work as (I) expected. I'm posting this here since: (A) the
problem might suggest a modification to the `m' component in the return
argument of `nls' (making this post formally OK for this list) and (B) I
got no
2009 Nov 29
1
optim or nlminb for minimization, which to believe?
I have constructed the function mml2 (below) based on the likelihood function described in the minimal latex I have pasted below for anyone who wants to look at it. This function finds parameter estimates for a basic Rasch (IRT) model. Using the function without the gradient, using either nlminb or optim returns the correct parameter estimates and, in the case of optim, the correct standard
2010 Jan 18
5
errors appears in my time Series regression fomula
Dear all,
I found really difficult with the time series questions, please help me with this monthly airline series!
I have run the following r code, and there is an error appeared at the end. The data files was enclosed in the email.
I'm sorry the errors message appeared in chinese, but it says "plot.xy(xy.coords(x, y), type = type, ...) :
errors in argument has more than 3
2008 Aug 17
1
before-after control-impact analysis with R
Hello everybody,
In am trying to analyse a BACI experiment and I really want to do it
with R (which I find really exciting). So, before moving on I though it
would be a good idea to repeat some known experiments which are quite
similar to my own. I tried to reproduce 2 published examples but without
much success. The first one in particular is a published dataset
analysed with SAS by
2010 Oct 04
1
Help with apply
Suppose I have the following data:
tmp <- data.frame(var1 = sample(c(0:10), 3, replace = TRUE), var2 = sample(c(0:10), 3, replace = TRUE), var3 = sample(c(0:10), 3, replace = TRUE))
I can run the following double loop and yield what I want in the end (rr1) as:
library(statmod)
Q <- 2
b <- runif(3)
qq <- gauss.quad.prob(Q, dist = 'normal', mu = 0, sigma=1)
rr1 <- matrix(0,
2012 Jul 15
1
how to extract p-value in GenMatch function
Dear R-Users,
I have a problem on extracting T-Stat and P-Value. I have written R-code below
library("Matching")
data("lalonde")
attach(lalonde)
names(lalonde)
Y <- lalonde$re78
Tr <- lalonde$treat
glm1 <- glm(Tr~age+educ+black+hisp+married+nodegr+re74+re75,family=binomial,data=lalonde)
pscore.predicted <- predict(glm1)
rr1 <-
2008 Sep 19
0
panel data analysis possible with mle2 (bbmle)?
Dear R community,
I want to estimate coefficients in a (non-linear) system of equations using
'mle2' from the "bbmle" package. Right now the whole data is read in as just
one long time series, when it's actually 9 cross sections with 30 observations
each. I would like to be able to test and correct for autocorrelation but
haven't found a way to do this in this package.
2009 Jul 06
1
transform multi skew-t to uniform distribution
Hi R-users,
I have a data from multi skew t and would like to transform each of the data to uniform data. I tried using 'pmst' but only got one output:
> rr1 <- as.vector(r1);rr1
[1] 0.7207582 5.2250906 1.7422237 0.5677233 0.7473555 -0.6020626 -2.1947872 -1.1128313 -0.6587316 -1.1409261
> pmst(rr1, xi=rep(0,10), Omega=diag(10), alpha=rep(1,10), df=5)
[1] 3.676525e-09
2003 Oct 18
1
why does data frame subset return vector
Hello,
I've a weired problem with a data frame. Basically it should be just one
column with
specific names coming from a data file (the file contains 2 rows, one should
be
the for the rownames of the data frame the other contains numeric values).
> df.rr <- read.table("RR_anova.txt", header=T, comment.char="", row.names=1)
> df.rr[c(1,2,3),]
[1] 1.11e-16 1.11e-16
2006 Jul 03
0
Questions concerning function 'svm' in e1071 package
Greetings everyone,
I have the following problem (illustrating R-code at bottom of mail):
Given a training sample with binary outcomes (-1/+1), I train a linear
Support Vector Machine to separate them. Afterwards, I compute the
weight vector w in the usual way, and obtain the fitted values as
w'x + b > 0 ==> yfitted = 1, otherwise -1.
However, upon verifying with the
2010 Sep 29
1
nlminb and optim
I am using both nlminb and optim to get MLEs from a likelihood function I have developed. AFAIK, the model I has not been previously used in this way and so I am struggling a bit to unit test my code since I don't have another data set to compare this kind of estimation to.
The likelihood I have is (in tex below)
\begin{equation}
\label{eqn:marginal}
L(\beta) = \prod_{s=1}^N \int
2012 Oct 22
1
Matlab code to R code
Dear r-users,
I would like to convert my Matlab code to R-code, however it dies not work as expected. Hope somebody can help me to match Matlab and r codes.
R code:
rr <- function(r,cxn)
{
tol <- 1E-4;
for(i in 1:n)
{
t1 <- (1+(i-1)*r)*log((1+(i-1)*r))
t2 <- (i-1)*(1-r)*log(1-r)
rri <- ((t1+t2)/i*log(i))-cxn
rr <- rri > tol
}
round(rr,4)
}
rr1 <- rr(0.5,0.0242) ; rr1
2012 Jul 10
1
RGL 3D curvilinear shapes
Dear useRs,
I'm trying to simply fill in the area under a curve using RGL. Here' the set
up:
x <- c(0.75,75.75,150.75,225.75,300.75,375.75,450.75,525.75,600.75,675.75,
0.5,50.5,100.5,150.5,200.5,250.5,300.5,350.5,400.5,450.5,
0.25,25.25,50.25,75.25,100.25,125.25,150.25,175.25,200.25,225.25)
y <- c(0.05,4.91,9.78,14.64,19.51,24.38,29.24,34.11,38.97,43.84,
1999 Dec 09
1
nlm() problem or MLE problem?
I am trying to do a MLE fit of the weibull to some data, which I attach.
fitweibull<-function()
{
rt<-scan("r/rt/data2/triam1.dat")
rt<-sort(rt)
plot(rt,ppoints(rt))
a<-9
b<-.27
fn<-function(p) -sum( log(dweibull(rt,p[1],p[2])) )
cat("starting -log like=",fn(c(a,b)),"\n")
out<-nlm(fn,p=c(a,b), hessian=TRUE)
2005 Nov 08
2
retrieve most abundant species by sample unit
Hi R-users:
[R 2.2 on OSX 10.4.3]
I have a (sparse) vegetation data frame with 500 rows (sampling
units) and 177 columns (plant species) where the data represent %
cover. I need to summarize the cover data by returning the names of
the most dominant and the second most dominant species per plot. I
reduced the data frame to omit cover below 5%; this is what it looks
like stacked. I have
2008 Aug 26
2
svymeans question
I have the following code which produces the output below it
clus1 <- svydesign(ids = ~schid, data = lower_dat)
items <- as.formula(paste(" ~ ", paste(lset, collapse= "+")))
rr1 <- svymean(items, clus1, deff='replace', na.rm=TRUE)
> rr1
mean SE DEff
W525209 0.719748 0.015606 2.4932
W525223 0.508228 0.027570 6.2802
W525035 0.827202
2004 Aug 25
3
Beginners Question: Make nlm work
Hello,
I'm new to this and am trying to teach myself some R by plotting
biological data. The growth curve in question is supposed to be fitted
to the Verhulst equation, which may be transcribed as follows:
f(x)=a/(1+((a-0.008)/0.008)*exp(-(b*x)))
- for a known population density (0.008) at t(0).
I am trying to rework the example from "An Introduction to R" (p. 72)
for my case and
2017 Oct 11
1
[PATCH v1 01/27] x86/crypto: Adapt assembly for PIE support
Change the assembly code to use only relative references of symbols for the
kernel to be PIE compatible.
Position Independent Executable (PIE) support will allow to extended the
KASLR randomization range below the -2G memory limit.
Signed-off-by: Thomas Garnier <thgarnie at google.com>
---
arch/x86/crypto/aes-x86_64-asm_64.S | 45 ++++++++-----
arch/x86/crypto/aesni-intel_asm.S
2008 Apr 22
3
[PATCH 0/3] ia64/pv_ops preparation
Hi. This patchset is preparation patches for ia64/pv_ops support.
They are almost trivial and mainly make kernel paravirtualization friendly.
thanks,
Diffstat:
arch/ia64/kernel/irq_ia64.c | 1 -
include/asm-ia64/intrinsics.h | 11 +++++++++++
include/asm-ia64/mmu_context.h | 6 +-----
include/asm-ia64/smp.h | 2 ++
include/asm-ia64/system.h | 10 ++++++++--
5 files