Displaying 20 results from an estimated 5000 matches similar to: ""simulate" does not include variability in parameter estimation"
2019 Dec 27
1
"simulate" does not include variability in parameter estimation
On 2019-12-27 04:34, Duncan Murdoch wrote:
> On 26/12/2019 11:14 p.m., Spencer Graves wrote:
>> Hello, All:
>>
>>
>> ? ????? The default "simulate" method for lm and glm seems to ignore the
>> sampling variance of the parameter estimates;? see the trivial lm and
>> glm examples below.? Both these examples estimate a mean with formula =
>>
2019 Dec 27
0
"simulate" does not include variability in parameter estimation
On 26/12/2019 11:14 p.m., Spencer Graves wrote:
> Hello, All:
>
>
> ????? The default "simulate" method for lm and glm seems to ignore the
> sampling variance of the parameter estimates;? see the trivial lm and
> glm examples below.? Both these examples estimate a mean with formula =
> x~1.? In both cases, the variance of the estimated mean is 1.
That's how
2012 Sep 10
1
usb port issue in 9.1-Prerelease (Possibly Cam related)
Hi Folks,
I've facing an intermittent hang with a USB port which seems cam
related:
Event's that happen are:
o USB modem (HUAWEI E220) plugged into PC
ugen3.2: <HUA WEI> at usbus3
u3g0: <3G Modem> on usbus3
u3g0: Found 3 ports.
umass0: <USB MASS STORAGE> on usbus3
umass0: SCSI over Bulk-Only; quirks = 0x0000
umass0:6:0:-1: Attached to scbus6
umass1: <USB
2010 Sep 01
1
Looks like a bug in subsetting of a complicated object
I don't understand what is happening! I have a (large) object sim1, an
matrix list
with dim c(101,101) where each element is an 3*3 matrix. I am
subsetting that with
a matrix coo, of dim c(100,2), of unique indices, but the resulting object
has length 99, not 100 as expected.
Code reproducing the problem follows:
library(RandomFields)
set.seed(123)
sim0 <- GaussRF(x=seq(0, 100, by=1),
2009 Apr 15
2
AICs from lmer different with summary and anova
Dear R Helpers,
I have noticed that when I use lmer to analyse data, the summary function
gives different values for the AIC, BIC and log-likelihood compared with the
anova function.
Here is a sample program
#make some data
set.seed(1);
datx=data.frame(array(runif(720),c(240,3),dimnames=list(NULL,c('x1','x2','y'
))))
id=rep(1:120,2); datx=cbind(id,datx)
#give x1 a
2008 Jul 23
1
Questions on weighted least squares
Hi all,
I met with a problem about the weighted least square regression.
1. I simulated a Normal vector (sim1) with mean 425906 and standard deviation 40000.
2. I simulated a second Normal vector with conditional mean b1*sim1, where b1 is just a number I specified, and variance proportional to sim1. Precisely, the standard deviation is sqrt(sim1)*50.
3. Then I run a WLS regression without the
2011 Oct 06
1
anova.rq {quantreg) - Why do different level of nesting changes the P values?!
Hello dear R help members.
I am trying to understand the anova.rq, and I am finding something which I
can not explain (is it a bug?!):
The example is for when we have 3 nested models. I run the anova once on
the two models, and again on the three models. I expect that the p.value
for the comparison of model 1 and model 2 would remain the same, whether or
not I add a third model to be compared
2006 Oct 08
1
Simulate p-value in lme4
Dear r-helpers,
Spencer Graves and Manual Morales proposed the following methods to
simulate p-values in lme4:
************preliminary************
require(lme4)
require(MASS)
summary(glm(y ~ lbase*trt + lage + V4, family = poisson, data =
epil), cor = FALSE)
epil2 <- epil[epil$period == 1, ]
epil2["period"] <- rep(0, 59); epil2["y"] <- epil2["base"]
2018 Jan 17
1
Assessing calibration of Cox model with time-dependent coefficients
I am trying to find methods for testing and visualizing calibration to Cox
models with time-depended coefficients. I have read this nice article
<http://journals.sagepub.com/doi/10.1177/0962280213497434>. In this paper,
we can fit three models:
fit0 <- coxph(Surv(futime, status) ~ x1 + x2 + x3, data = data0) p <-
log(predict(fit0, newdata = data1, type = "expected")) lp
2006 Feb 27
1
Different deviance residuals in a (similar?!?) glm example
Dear R-users,
I would like to show you a simple example that gives an overview of one
of my current issue.
Although my working setting implies a different parametric model (which
cannot be framed in the glm), I guess that what I'll get from the
following example it would help for the next steps.
Anyway here it is.
Firstly I simulated from a series of exposures, a series of deaths
(given a
2011 May 08
1
anova.lm fails with test="Cp"
Here is an example, modified from the help page to use test="Cp":
--------------------------------------------------------------------------------
> fit0 <- lm(sr ~ 1, data = LifeCycleSavings)
> fit1 <- update(fit0, . ~ . + pop15)
> fit2 <- update(fit1, . ~ . + pop75)
> anova(fit0, fit1, fit2, test="Cp")
Error in `[.data.frame`(table, , "Resid.
2018 Jan 18
1
Time-dependent coefficients in a Cox model with categorical variants
First, as others have said please obey the mailing list rules and turn of
First, as others have said please obey the mailing list rules and turn off html, not everyone uses an html email client.
Here is your code, formatted and with line numbers added. I also fixed one error: "y" should be "status".
1. fit0 <- coxph(Surv(futime, status) ~ x1 + x2 + x3, data = data0)
2. p
2011 Sep 12
1
coxreg vs coxph: time-dependent treatment
Dear List,
After including cluster() option the coxreg (from eha package)
produces results slightly different than that of coxph (from survival)
in the following time-dependent treatment effect calculation (example
is used just to make the point). Will appreciate any explaination /
comment.
cheers,
Ehsan
############################
require(survival)
require(eha)
data(heart)
# create weights
2005 May 07
1
Test on mu with multivariate normal distribution
Dear WizaRds,
I am sorry to bother you with a newbie question, but although I tried to solve my problem using the various .pdf files (Introduction, help pages etc.), I have come to a complete stop. Please be so kind as to guide me a little bit along my way of exploring multivariate analysis in R.
I want to test wether the means-vector mu1 of X, consisting of the means per column of that matrix
2006 Aug 30
1
Optimization
Dear R-list,
I'm trying to estimate the relative importance of 6 environmental variables
in determining clam yield. To estimate clam yield a previous work used the
function Yield = (A^a*B^b*C^c...)^1/(a+b+c+...) where A,B,C... are the
values of the environmental variables and the weights a,b,c... have not been
calibrated on data but taken from literature. Now I'd like to estimate the
2004 Apr 14
4
Non-Linear Regression Problem
Dear all,
I was wondering if there is any way i could do a "Grid Search" on a
parameter space using R (as SAS 6.12 and higher can do it) to start the
Newton-Gauss Linearization least squares method when i have NO prior
information about the parameter.
W. N. Venables and B. D. Ripley (2002) "Modern Applied Statistics with S",
4 th ed., page 216-7 has a topic
2007 Feb 20
1
testing slopes
Hello
Instead of testing against 0 i would like to test regression slopes against -1. Any idea if there's an R script (package?) available.
Thanks for any hint.
Cheers
Lukas
???
Lukas Indermaur, PhD student
eawag / Swiss Federal Institute of Aquatic Science and Technology
ECO - Department of Aquatic Ecology
?berlandstrasse 133
CH-8600 D?bendorf
Switzerland
Phone: +41 (0) 71 220
2006 Aug 17
1
Simulate p-value in lme4
Dear list,
This is more of a stats question than an R question per se. First, I
realize there has been a lot of discussion about the problems with
estimating P-values from F-ratios for mixed-effects models in lme4.
Using mcmcsamp() seems like a great alternative for evaluating the
significance of individual coefficients, but not for groups of
coefficients as might occur in an experimental design
2006 Nov 13
3
Profile confidence intervals and LR chi-square test
System: R 2.3.1 on Windows XP machine.
I am building a logistic regression model for a sample of 100 cases in
dataframe "d", in which there are 3 binary covariates: x1, x2 and x3.
----------------
> summary(d)
y x1 x2 x3
0:54 0:50 0:64 0:78
1:46 1:50 1:36 1:22
> fit <- glm(y ~ x1 + x2 + x3, data=d, family=binomial(link=logit))
>
2009 Jul 25
1
A Harder Score Test Question
Does anyone know how get the score and information under the null from
coxph? I know that I can get the chi-square value of the score from coxph,
but I need the two components separately. I have a function that computes
the two components when I do not have ties but I would like to leverage the
options(ties and strata components) already available in the coxph function.
The function coxph.detail