Displaying 20 results from an estimated 8000 matches similar to: "Graybill-Bowden confidence band"
2009 Sep 09
1
Stats help with calculating between and within subject variance and confidence intervals
Hello.
I'm trying to find a way in R to calculate between and within subject
variances and confidence intervals for some analytical method
development data.
I've found a reference to a method in Burdick, R. K. & Graybill, F. A.
1992, Confidence Intervals on variance components, CRC Press. This
example is for Balanced Data confidence interval calculation from Pg
62. The data are
2010 Jan 06
0
Unconsistent behaviour of function cor()
Odd behaviour of function cor() in R-2.10.1-64bit-Unix
In a dataset with 1366 patients and 244 clinical variables Spearman's Rho
was calculated for some fatty acids and BMI and came over something rather
odd:
R seems to calculate Rho differently on 2.10.1-64bit-Unix and
2.9.0-32bit-Windows when I calculate the complete (244x244) correlation
matrix and then pick out the values I am
More clear statement about the question of how to generate regression matrix with correlation matrix
2003 Jul 12
1
More clear statement about the question of how to generate regression matrix with correlation matrix
Dear R community:
I am trying to do a simulation study mentioned by Fu (1998), Journal of Computational and Graphical Statistics, Volume7, Number 3, Page 397-416. In order to give a clear statement of quesion I copy the following paragraph from the article: We compare the bridge model with the OLS, the lasso and the ridge in a simulation of a linear regression model of 30 observations and 10
2010 Jun 09
1
bug? in stats::cor for use=complete.obs with NAs
Arrrrr,
I think I've found a bug in the behavior of the stats::cor function when
NAs are present, but in case I'm missing something, could you look over
this example and let me know what you think:
> a = c(1,3,NA,1,2)
> b = c(1,2,1,1,4)
> cor(a,b,method="spearman", use="complete.obs")
[1] 0.8164966
> cor(a,b,method="spearman",
2000 Mar 14
1
qr.solve (fwd)
Two friend reported me a problem, which I can't solve:
(I run R-1.0.0, Debian Linux)
They hava a function "corr.matrix" (see end of mail), and when they
create a 173x173 matrix with this function
V <- corr.matrix(0.3, n=173)
V1 <- qr.solve(V)
reports:
Error in qr(a, tol = tol) : NA/NaN/Inf in foreign function call (arg 1)
For n < 173, qr.solve returns the correct
2008 Sep 26
0
Confidence interval for binomial variance
Based on simulations, I've come up with a simple function to compute
the confidence interval for the variance of the binomial variance,
where the true variance is
v = rho*(1-rho)/n
where rho = true probability of success and n = # of trials.
For x = # successes observed in n trials, p = x / n as usual.
For p < 0.25 or p > 0.75, I use the proportion-based transformed
confidence
2007 Mar 07
2
where can I find Durbin-Waston test tables for Confidence Level 2.5% or 0.5%?
Hi all,
I am doing a two-sided DW test:
H0: rho = 0
H1: rho =/= 0
My understanding is that most test statistics tables are one-sided. It's the
way they created the table.
So from online, by doing Googling, I found a bunch of DW tables for
Confidence Level 5%.
Those tables can answer my two-sided question at 5x2 = 10% confidence level.
But what if I want two-sided test at 1% and 5%
2008 Jun 05
1
memory.size() for large memory usage (PR#11596)
This amusing behaviour is from R2.6.1 on WinXP Pro SP2 running with boot.in=
i /3GB flag, exploring memory limits.
=20
When actual (object, not total) memory usage hits 2048 MB, memory.size star=
ts counting down again, but reports a negative amount, e.g. -2046.333. Is t=
his an intended (or unavoidable) feature?)
=20
Thanks,
=20
Rory Bowden
bowden at stats.ox.ac.uk
=20
[[alternative
2006 Dec 01
3
error in hetcor function (polycor package)?
I have been using the hetcor function in the polycor package. When I
don't specify the use option everything runs smoothly. However, when I
specify use either as "pairwise.complete.obs" or "complete.obs" I get
this error
Error in optim(rho, f, control = control, hessian = TRUE, method =
"BFGS") :
non-finite value supplied by optim
Is this an error in
2005 Jul 08
2
time series regression
Hi:
I have two time series y(t) and x(t). I want to
regress Y on X. Because Y is a time series and may
have autocorrelation such as AR(p), so it is not
efficient to use OLS directly. The model I am trying
to fit is like
Y(t)=beta0+beta1*X(t)+rho*Y(t-1)+e(t)
e(t) is iid normal random error. Anybody know whether
there is a function in R can fit such models? The
function can also let me specify
2023 Nov 15
2
Cannot calculate confidence intervals NULL
R-Experts,
Here below my R code working without error message but I don't get the results I am expecting.
Here is the result I get:
[1] "All values of t are equal to 0.28611928397257 \n Cannot calculate confidence intervals"
NULL
If someone knows how to solve my problem, really appreciate.
Best,
S
#########################################################
# Difference in Spearman
2007 Jan 06
1
help with gls
Hello R-users,
I am using gls function in R to fit a model with certain correlation
structure.
The medol as:
fit.a<-gls(y~1,data=test.data,correlation=corAR1(form=~1|aa),method="ML")
mu<-summary(fit.a)$coefficient
With the toy data I made to test, the estimate of mu is exactly equal to
the overall mean of y which can not be true.
But, if I make a toy data with y more than two
2023 Nov 15
1
Cannot calculate confidence intervals NULL
I believe the problem is here:
cor1 <- cor(x1, y1, method="spearman")
cor2 <- cor(x2, y2, method="spearman")
The x's and y's are not looked for in data (i.e. NSE) but in the
environment where the function was defined, which is standard evaluation.
Change the above to:
cor1 <- with(d, cor(x1, y1, method="spearman"))
cor2 <- with(d, cor(x2, y2,
2005 Oct 24
2
Spearman's Rho Help!
Hi,
I have a dataset with four categories of data, the number of samples are not
the same in each category. I want to find the Spearaman's Rho. Let me give
an example.
x=(14.22770439,26.49420624,46.7277932,19.02550707,23.37379361,16.97789862,19.77100085,23.11270162,13.72929843,33.54430621,14.4756979,70.15811106,11.22789833,NA,NA,NA)
2003 Mar 26
2
[Bug 521] PAM authentication not working in privilege seperation mode running in trusted system on hp-ux
http://bugzilla.mindrot.org/show_bug.cgi?id=521
Summary: PAM authentication not working in privilege seperation
mode running in trusted system on hp-ux
Product: Portable OpenSSH
Version: 3.5p1
Platform: HPPA
OS/Version: HP-UX
Status: NEW
Severity: major
Priority: P2
Component: sshd
2008 Dec 19
1
obtaining output from an evaluated expression
Hi
I am trying to use the deriv and eval functions to obtain the value of a
function , say "xi-(alpha0+alpha1*gi)" , differentiated with respect to
alpha0 and alpha1, in the following way
# for gi = 0
> dU1dtheta <- deriv(~ xi-(alpha0+alpha1*gi), c("alpha0","alpha1"))
> eval(dU1dtheta)
(Intercept)
-0.2547153
attr(,"gradient")
2012 Mar 01
1
Execution of Rprofile.site
Hi everyone. I have recently installed R 2.14.1 on my 64-bit Windows 7
laptop. I am attempting to include some favourite functions in the
Rprofile.site file to run at R start-up as I did with my previous 32-bit
XP machine. I have edited the Rprofile.site file in "C:\Program
Files\R\R-2.14.1\etc\" but the added code doesn't seem to be executed
when I run R, whether through Tinn-R
2010 Mar 27
0
data fitting and confidence band
Hello,
I am fitting data using different methods e.g. Local Polynomial and Smoothing splines. The data is generated out of a true function model with added normally distributed noise.
I would like to know "how often the confidence band for all points simultaneously contain all true values". I can answer the question for one point in the following way:
e.g.
#
2009 Apr 22
4
plot confidence intervals as shaded band
Hi,
does anyone know how do I plot confidence intervals as a shaded band around a curve, rather than as errors bars?
many thanks,
ulisses.
[[alternative HTML version deleted]]
2005 Oct 24
1
locfit: simultaneous confidence band
I'm using the package 'locfit' for nonparametric regression. This package
contains the function 'scb' to compute simultaneous confidence bands.
The variance of the data is unknown. Up to now I compute a fit with
'locfit'. Afterwards an estimate of the residual variance is computed by the
function 'rv'. The weights in the 'scb'-function are set 1/sigma^2