similar to: group sequential and adaptive designs

Has anyone tried to download Hmisc and used ldBands function for calculating Lan-Demets group sequential boundaries? The write-up in F.Harrell's website indicates that, besides downloading the package Hmisc, one needs to copy the progra ld98 from the University of Wisconsin website. As suggested, I did this but received another error message regarding the search path. I think I have fixed

Hello My Fellow Users, Under the details it is given that the ld98 executable should be in a subdirectory that is in the system. Should ld98.exe be included under Hmisc (where it is stored) or under the lib subdirectory within Hmisc? I am getting the following error message: Error in (head + 1):length(w) : NA/NaN argument. Does this mean that I didn't store the ld98.exe in the right place

Dear R users, can someone help with these short puzzles? 1) Is there a function like outer() that evaluates a three-argument function on a threedimensional grid - or else how to define such a function, say, outer.3()? E.g., calculate (x/y)^z on (x,y,z) element of {1,2,3}x{3,4}x{4,5} and return the results in a 3-dimensional array. I would naively use outer() on two of the arguments within a

Dear R programmers, is there a sensible explanation for the following behaviour? The second command seems not to be interpreted correctly. > seq(0.6, 0.9, by=0.1) == 0.8 [1] FALSE FALSE TRUE FALSE > seq(0.7, 0.9, by=0.1) == 0.8 [1] FALSE FALSE FALSE > c(0.7, 0.8, 0.9) == 0.8 [1] FALSE TRUE FALSE > seq(0.9, 0.7, by=-0.1) == 0.8 [1] FALSE TRUE FALSE I am running R version 1.7.1 on

Hello Everyone,   I’m a SAS user who has recently become interested in sequential clinical trials designs. I’ve discovered that the SAS based approaches for these designs are either too costly or are “experimental.” So now I’m looking for alternative software. Two programs that seem promising are SPLUS Seqtrial and R.   I recently obtained a 30 day trial for the SPLUS Seqtrial add-on and have

All, I'm getting the same error message as that discussed in a previous post (Feb 3, 2006). The reply to that post was to insure that the ld98 program was in the system path (as also suggested in the help on ldBands). I have done this but this does not change the result. Any advice much appreciated. David > sessionInfo() R version 2.7.2 (2008-08-25) i386-pc-mingw32 locale:

Dear List, I recently asked about any R implementations of Whitehead's methods for sequential clinical trials. Here's the summary of answers so far : 1) There is no R public implementation of those methods 2) There exists an interest for such a package, which does things quite different from Lan-deMets paradigm (shortly : Whitehead's methods allows for unplanned interim analyses

Following up to some extent on Friday's discussion regarding the 'validation' of R, could I ask the list group's opinion on possible advantages of R over Splus from a pharma/devices perspective? I wish to exclude the obvious price difference, which doesn’t seem to carry as much weight as I would have thought. Besides, I have noticed many former Splus users gravitating towards R,

Hi all! I would like to import a matlab or gauss code to R. Could you help me? Bye, Sebasti?n. 2007/6/23, r-help-request en stat.math.ethz.ch <r-help-request en stat.math.ethz.ch>: > Send R-help mailing list submissions to > r-help en stat.math.ethz.ch > > To subscribe or unsubscribe via the World Wide Web, visit >

Dear R users, I created a program for a simulation. It produces datasets and then it conducts some fits with the function coxph. Sometimes this function produces warnings, but I get only this warnings after finishing my program. Is there any possibility to get these hints earlier, maybe at once after the fit? I tried to store that during my program, but warnings() doesn't work. Thanks for

CRAN (and crantastic) updates this week New packages ------------ * bdoc (1.0) Michael Anderson http://crantastic.org/packages/bdoc This package contains a function that will classify DNA barcodes as well as a few test and reference data sets. * bdsmatrix (1.0) Terry Therneau http://crantastic.org/packages/bdsmatrix This is a special case of sparse matrices, used by coxme and

Hello List: Please find uploaded to CRAN a new package, PwrGSD The package is intended for the design and analysis of group sequential trials There are two main functions, (1) GrpSeqBnds: computes group sequential stopping boundaries for interim analysis of a sequential trial based upon a normally distributed test statistic. This can be done via the Lan-Demets procedure with

Hello List: Please find uploaded to CRAN a new package, PwrGSD The package is intended for the design and analysis of group sequential trials There are two main functions, (1) GrpSeqBnds: computes group sequential stopping boundaries for interim analysis of a sequential trial based upon a normally distributed test statistic. This can be done via the Lan-Demets procedure with

[my original message to s-news & r-help is attached ] No one possessed or knew of any S/R code for the sequential t-test. Also it doesn't appear in the SAS index. One or two suggested obtaining the S+ seqtrial software which may (or may not) cover this, but this seemed to be a bit of a "hammer to crack a nut". I have written a function based on the treatment in Wetheril

Hi R users: How can I obtain the same "anova" table for the effects for a 2^k experiment design that MINITAB shows (and authors recommends Box, Hunter, & Hunter). http://www.stat.psu.edu/online/development/stat503/06_2k/04_2k_unreplicate.html Here is the code that I use for this case: D<-C<-B<-A<-c("-","+") design<-expand.grid(A=A,B=B,C=C,D=D)

Hi R users: I want to know if there is any package that makes the specific computation 2^k factorial designs as in: George E. P. Box, J. Stuart Hunter and William G. Hunter. Statistics for Experimenters. Second Edition. 2005. John Wiley & Sons. They advice about the misuse of the ANOVA table in this kind of designs in page 188. Thank you for your help. Kenneth

Dear R users, I am pleased to announce the release of a new packaged called `bcrm? (version 0.1), now available on CRAN. The package implements a wide range of Bayesian continuous reassessment method (CRM) designs to be used in Phase I dose-escalation trials. The package is fully documented and highlights include ? A choice of 1-parameter working models or the 2-parameter logistic model.

Dear R users, I am pleased to announce the release of a new packaged called `bcrm? (version 0.1), now available on CRAN. The package implements a wide range of Bayesian continuous reassessment method (CRM) designs to be used in Phase I dose-escalation trials. The package is fully documented and highlights include ? A choice of 1-parameter working models or the 2-parameter logistic model.

Hi All, recently I used Design Expert for some Design Of Experiment work. I was happy with the interface to select which effects I want to see in my experiment, and which not. For example: I can select of course my main effects, but also if I want to see interaction A:B, B:C, A:B:C,but not A:C. This was very interessting as you can end up with fewer runs, especially in cases of 10 factors with

I am wondering if in a block experimental design (ex. triple square lattice), the block effect was not significant, is it all right not to include the block effect in an empirical model (even though the sampling was done from different blocks)? Or we are forced to control for the block effect in block designs anyway? Thanks, Julia