Displaying 20 results from an estimated 1000 matches similar to: "Incomplete Factorial design"
2004 Nov 09
3
Strange results for Beta Distribution
Dear All,
I got these results from the example in the function "dbeta":
>x <- seq(0, 1, length=21)
> dbeta(x, 1, 1)
[1] 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
Any Idea?
TIA
Giovanni
dr. Giovanni Parrinello
Section of Medical Statistics
Department of Biosciences
University of Brescia
25127 Viale Europa, 11
Brescia Italy
Tel: +390303717528
Fax: +390303701157
2008 Feb 07
1
Appell Hypergeometric function
Dear All,
I am looking for an implementation in R of the Appell Hypergeometric
function.
Any suggestions will be more than appreciated!
GP
--
dr. Giovanni Parrinello
External Lecturer
Medical Statistics Unit
Department of Biomedical Sciences
Viale Europa, 11 - 25123 Brescia Italy
Tel: +390303717528
Fax: +390303717488
email: parrinel at med.unibs.it
2007 Jun 08
6
"R is not a validated software package.."
Dear All,
discussing with a statistician of a pharmaceutical company I received
this answer about the statistical package that I have planned to use:
As R is not a validated software package, we would like to ask if it
would rather be possible for you to use SAS, SPSS or another approved
statistical software system.
Could someone suggest me a 'polite' answer?
TIA
Giovanni
--
dr.
2008 May 12
4
Left censored responses in mixed effects models
Dear R Fellow-Travellers:
What is your recommended way of dealing with a left-censored response
(non-detects) in (linear Gaussian) mixed effects models?
Specifics: Response is a numeric positive measurement (of volume, actually);
but when it falls below some unknown and slightly random value (depending on
how the sample is prepared and measured), it cannot be measured and is
recorded as 0.
2006 Nov 30
1
update.packages
Dear All,
from some days when I try to update the installed packages I receive
this answer:
update.packages(ask='graphics')
--- Please select a CRAN mirror for use in this session ---
Error in as.list(read.dcf(file = file)[1, ]) :
indice fuori limite # index out of bound
TIA
Giovanni
PS: I have already tried to solve the problem reinstalling R or changing
the options of
2006 Sep 22
1
Propensity score and three treatments
Dear All,
I would like to find something ( references, code,..) to implement a
comparison of three
treatments in an observational study using the 'Propensity Score'.
Any help is much appreciated. Thanks!
Giovanni
--
dr. Giovanni Parrinello
Department of Biotecnologies
Medical Statistics Unit
University of Brescia
Viale Europa, 11 25123 Brescia
email: parrinel at med.unibs.it
Phone:
2007 Jan 05
1
Error in load
Dear All,
can anyone explain this message
Error in load("matched2.RData") : Value of SET_STRING_ELT() must be a
'CHARSXP' not a 'builtin'?
Have I the possibility to retrieve the data?
TIA
Giovanni
--
dr. Giovanni Parrinello
Department of Biotecnologies
Medical Statistics Unit
University of Brescia
Viale Europa, 11 25123 Brescia
email: parrinel at med.unibs.it
Phone:
2009 Jan 14
1
problems with Sweave and the function latex(HMISC)
latex(s6a2,title="",caption="Baseline vs
zonr",file="",label="Base",long=TRUE,landscape=F, middle.bold=TRUE,here=T,
+
,size="smaller[5]",outer.size="smaller",Nsize="smaller",midsize="smaller")
"latex" is not reconized \as a internalor external command ,
un programma eseguibile o un file batch.
Warning
2002 Nov 23
0
Library QVF from Carroll et al.
Dear All,
I am looking for the library QVF [ NONLINEAR MEASUREMENT ERROR PROGRAMS FOR
SAS AND SPLUS ].
TIA
Giovanni Parrinello
dr. Giovanni Parrinello
Medical Statistics Unit
Department of Medical Sciences
University of Brescia
Via Valsabbina, 19
25127 Brescia
Italy
tel.: +39303717528
fax:+39303701157
E-mail: parrinel at med.unibs.it
url: http://www.med.unibs.it/dip/stat/index.html
2005 Nov 30
3
Random Effects for One-Way Anova
Hello to All.
I'd want to use a one-way ANOVA. This means that I have only one factor, with,
lets say, 5 levels.
I made a dataframe, called "DATA", with two Columns:
A, that is my response, and it is "class numerical".
B, that defines the different levels of my factor, and it is "class factor".
If I want to use a fixed effect model,
I know that the formula I have
2006 Jan 18
2
Loading of namespace on load of .Rdata (was strange behaviour of load)
Last week Giovanni Parrinello posted a message asking why various packages were loaded when he loaded an .Rdata file. Brian Ripley replied saying he thought it was because the saved workspace contained a reference to the namespace of ipred. (Correspondence copied below).
This begs the question: how did the reference to the namespace of ipred come to be in the .Rdata file? Brian did say it is
2005 Nov 22
2
residuals.coxph
Dear All,
I am trying to apply the function 'cox.zph' of the library survival, but I receive this error message:
not found the object 'residuals.coxph'.
I have re-installed the library 'survival' without any change and also a search with RSiteSearch was unsuccessful..
Any suggestion?
TIA
Giovanni
PS:
R 2.2.0
Windows XP HE
dr. Giovanni Parrinello
Section of Medical
2006 Jan 11
1
Strange behaviour of load
Dear All,
simetimes when I load an Rdata I get this message
#######
Code:
load('bladder1.RData')
Carico il pacchetto richiesto: rpart ( Bad traslastion: Load required package-...)
Carico il pacchetto richiesto: MASS
Carico il pacchetto richiesto: mlbench
Carico il pacchetto richiesto: survival
Carico il pacchetto richiesto: splines
Carico il pacchetto richiesto: 'survival'
2003 Nov 18
5
mixed model for Splus and R
Hi there,
I try to compare the mixed model package "lme" by Splus and R. I used the
dataset "Ovary" and the following code assuming AR(1) model for the error term:
lme(follicles ~ sin(2*pi*Time) + cos(2*pi*Time), data=Ovary, random =
pdDiag(~sin(2*pi*Time) ) , correlation=corAR1() )
But I got different results! And then I used a simpler model:
lme(follicles ~
2009 May 04
1
Nelson-Aalen estimator of cumulative hazard
Hi,
I am computing the Nelson-Aalen (NA) estimate of baseline cumulative hazard in two different ways using the "survival" package. I am expecting that they should be identical. However, they are not. Their difference is a monotonically increasing with time. This difference is probably not large to make any impact in the application, but is annoyingly non-trivial for me to just
1998 Feb 16
2
Printer errors
Hello all,
Got SAMBA running on a linux 2.0.32 box, and all is well. Looked over the
docs and set up my printer with the (what I think) are correct entries.
Basically, what the default smb.conf has. Testparms says it o.k.! And I
can print (lpr) locally.
Windows sees both printcap entries (inkjet and psjet), but any attempt to
pring to them errors out. I then added the print command =
2004 Jan 28
5
Julian dates
Hi all,
I have problems with years of dates using "chron" package.
I don't understand why R by this istruction:
> dates("01/02/29",out.format="d/m/year")
[1] 02/Jan/2029
> dates("01/02/30",out.format="d/m/year")
[1] 02/Jan/1930
reads "29" as 2029
and "30" as 1930. How could I change to read "00" to
2002 Sep 13
0
Sample size for factorial clinical trials with survival endpoints
Dear All,
I am looking an R version of the "Computer program for sample size and
power calculations in the design of multi-arm and factorial clinical trials
with survival endpoints".
Best regards,
Giovanni Parrinello
P.S.: in the meantime I am preparing a summary for my preceeding question
about time-varying covariates in the Cox model and
I thank Frank Harrell, Chuck Cleland,
2005 Nov 09
8
Element-by-element multiplication operator?
Is there an element-by-element multiplication in R, like the .* operator in Matlab?
eg: A (2x3)
B (2x3)
C=A.*B
C (2x3)
C = [[a11*b11 a12*b12 a13*b13]; [a21*b21 a22*b22 a23*b23]]
I can't find one...
Thanks
-Mike Gates
2009 Mar 03
1
R - need more memory, or rejection sampling algorithm doesn't work?
Hi all,
I am trying to run rejection sampling for the quantity z11 in the function
below. Unfortunately I can't simplify the function further so that z11 only
appears once.
Whenever I run the algorithm, R looks as if it is running it (no error
messages or anything), but then nothing happens for minutes...how long
should it take to run something like this in R? I have tried in in both
linux