similar to: One-arm survival sample estimates

Displaying 20 results from an estimated 1000 matches similar to: "One-arm survival sample estimates"

2006 Jul 26
2
R vs. Stata
I have read some very good reviews comparing R (or Splus) to SAS. Does anyone know if there are any reviews comparing R (or Splus) to Stata? I am trying to get others to try R in my department, and I have never used Stata. Regards, -Cody Cody Hamilton, Ph.D Institute for Health Care Research and Improvement Baylor Health Care System (214) 265-3618 This e-mail, facsimile, or letter
2008 May 02
0
Adaptive design code
I have been trying to create code to calculate the power for an adaptive design with a survival endpoint according to the method of Schafer and Muller ('Modification of the sample size and the schedule of interim analyses in survival trials based on interim inspections,' Stats in Med, 2001). This design allows for the sample size to be increased (if necessary) based on an interim look at
2006 Jul 05
3
Invoking SAS in order to use sas.get
I am trying to use the sas.get function to bring a SAS dataset into R. After calling the sas.get function I got an error message stating that 'sas' is not a recognized internal or external command, etc. I am guessing that I need to specify the internal command to invoke SAS in the sasprog option for the sas.get function, but I don't know how to determine what that command might be.
2006 Jun 16
6
modeling logit(y/n) using lrm
I have a dataset at a hospital level (as opposed to the patient level) that contains number of patients experiencing events (call this number y), and the number of patients eligible for such events (call this number n). I am trying to model logit(y/n) = XBeta. In SAS this can be done in PROC LOGISTIC or GENMOD with a model statement such as: model y/n = <predictors>;. Can this be done
2006 Jul 21
0
One arm survival sample calculations
Does anyone know of a function that computes the necessary sample size to reject a null median survival in favor of a given alternative median survival in a one arm trial? Cody Hamilton, Ph.D Institute for Health Care Research and Improvement Baylor Health Care System (214) 265-3618 This e-mail, facsimile, or letter and any files or attachments transmitted with it contains information
2006 Jul 07
6
parametric proportional hazard regression
Dear all, I am trying to find a suitable R-function for parametric proportional hazard regressions. The package survival contains the coxph() function which performs a Cox regression which leaves the base hazard unspecified, i.e. it is a semi-parametric method. The package Design contains the function pphsm() which is good for parametric proportional hazard regressions when the underlying base
2003 May 15
0
Re: list GRASSLIST: List Message Rejected
I appologise sincerly, will not happen again. mr. Ripley: Your suggestions were helpful, thanks. I figured I haven not installed the devel RPMS. >From: Prof Brian Ripley <ripley at stats.ox.ac.uk> >To: listproc at baylor.edu >CC: grass-request at baylor.edu, Miha STAUT <mihastaut at hotmail.com> >Subject: Re: list GRASSLIST: List Message Rejected >Date: Thu, 15 May
2011 Sep 21
1
Power calculation for survival analysis
useR's, I am trying to do a power calculation for a survival analysis using a logrank test and I need some help properly doing this in R. Here is the information that I know: - I have 2 groups, namely HG and LG - Retrospective analysis with subjects gathered from archival data over 20 years. No new recruitment of subjects and no estimated time to target accrual and accrual rate. - Survival
2004 Sep 06
1
qchisq (PR#7212)
Full_Name: David Clayton Version: 1.8.1 OS: Linux Submission from: (NULL) (131.111.126.242) qchisq behaves very strangely when ncp is passed as zero (forcing internal qnchisq to be called) when first argument is small. Eg > qchisq(1-1e-6, 1, ncp=0, lower.tail=TRUE) qchisq(1-1e-6, 1, ncp=0, lower.tail=TRUE) [1] 1024 while, if ncp is unspecified, > qchisq(1-1e-6, 1) qchisq(1-1e-6, 1)
2010 Nov 12
1
what's wrong with this 'length' in function?
Hi all, I am having a trouble with this function I wrote ################################################### p26=function(x,alpha){ # dummy variable j=1 ci=matrix(ncol=2,nrow=3) while (j<4){ if (j==2) {x=x+c(-1,1)*0.5} ci[j,]= x+qnorm(1-alpha/2)^2/2+ c(-1,1)*qnorm(1-alpha/2)* sqrt(x+qnorm(1-alpha/2)^2/4) j=j+1 if (j==3) { # exact x=x-c(-1,1)*0.5
2004 Jan 19
2
small bug on qchisq (PR#6442)
Full_Name: Drouilhet R?my Version: 1.8.1 OS: Linux Submission from: (NULL) (195.221.43.136) qchisq(1,10) works well but qchisq(1,10,ncp=0) does not work whereas ncp=0 is the default value of the function qchisq(1,10). (of course, 10 will be replaced by any integer value). Let us notice that this bug occurs only when applying probability one. (qchisq(seq(0,.9,.1),10,ncp=0) works very well).
2009 Oct 11
2
Accuracy (PR#13999)
Full_Name: Viktor Witkovsky Version: 2.9.2 OS: Windows XP Submission from: (NULL) (78.98.89.227) Hello, I have found strange behavior of the function qchisq (the non-central qchisq is based on inversion of pchisq, which is further based on pgamma). The function gives wrong results without any warning. For example: qchisq(1e-12,1,8.94^2,lower.tail=FALSE) gives 255.1840972465858 (notice that
2007 Jun 14
0
Confidence interval for coefficient of variation
This is a function I coded a few years ago to calculate a confidence interval for a coefficient of variation. The code is based on a paper by Mark Vangel in The American Statistician. I have not used the function much, but it could be useful for comparing cv's from different groups. Kevin Wright confint.cv <- function(x,alpha=.05, method="modmckay"){ # Calculate the
2019 Feb 19
0
elasticsearch connection refused
Selinux will not allow connections on other than default http ports. semanage port -m -t http_port_t -p tcp 9200 Andrea -----Original Message----- From: CentOS [mailto:centos-bounces at centos.org] On Behalf Of Ralf Prengel Sent: Tuesday, February 19, 2019 8:09 AM To: centos at centos.org Subject: {EXTERNAL} Re: [CentOS] elasticsearch connection refused Am 19.02.2019 um 13:55 schrieb Ionut
2019 Apr 11
2
When will CentOS 8 be available for download?
RHEL 8 will be released during Redhat summit May 7-9. Andrea -----Original Message----- From: CentOS [mailto:centos-bounces at centos.org] On Behalf Of Gordon Messmer Sent: Wednesday, April 10, 2019 6:13 PM To: centos at centos.org Subject: {EXTERNAL} Re: [CentOS] When will CentOS 8 be available for download? On 4/10/19 3:51 PM, Turritopsis Dohrnii Teo En Ming wrote: > When will CentOS 8
2005 Aug 26
3
Matrix oriented computing
Hi, I want to compute the quantiles of Chi^2 distributions with different degrees of freedom like x<-cbind(0.005, 0.010, 0.025, 0.05, 0.1, 0.5, 0.9, 0.95, 0.975, 0.99, 0.995) df<-rbind(1:100) m<-qchisq(x,df) and hoped to get back a length(df) times length(x) matrix with the quantiles. Since this does not work, I use x<-c(0.005, 0.010, 0.025, 0.05, 0.1, 0.5, 0.9, 0.95, 0.975,
2020 Jul 31
0
8.2.2004 Latest yum update renders machine unbootable
RedHat is recommending not to patch. https://access.redhat.com/solutions/5272311 Andrea -----Original Message----- From: CentOS <centos-bounces at centos.org> On Behalf Of Alessandro Baggi Sent: Friday, July 31, 2020 11:25 AM To: centos at centos.org Subject: {EXTERNAL} Re: [CentOS] 8.2.2004 Latest yum update renders machine unbootable CAUTION:??This email originated outside of BSWH;
2007 Mar 08
2
augPred in lmer
I read the posts about augPred with lme, but does anyone know if there is a correlate for augPred for lmer? Specifically, I want to be able to use it to plot projections for all groups in an lmer class object using plot(augPred(lmer.object)). Thanks, Kyle *************************************** J. Kyle Roberts, Ph.D. Baylor College of Medicine Center for Educational Outreach One Baylor Plaza,
2008 Apr 08
1
sample size for log-rank test with more than 2 groups
Hi everyone, I was wondering whether extension of the current spower function for Hmisc were existing? My current focus is to calculate sample size based on the log-rank test with more than 2 groups (with/without trend) Taking into account the loss of follow up and the accrual processes. A SPSS library (ART) is existing but can't find anything in R Any information is welcome ! Many
2003 Jun 04
1
RE: Your application (PR#3190)
Stop sending me emails!!! > -----Original Message----- > From: r-bugs@lists.r-project.org [SMTP:r-bugs@lists.r-project.org] > Sent: Wednesday, 4 June 2003 16:28 > To: sam.taylor@chh.co.nz > Subject: Re: Your application > > Please see the attached file. << File: DELETED0.TXT >> DISCLAIMER: This electronic message together with any attachmen... {{dropped}}