[R] gsDesign Pocock & OBF boundary

Jeff Newmiller jdnewmil at dcn.davis.ca.us
Sun Sep 24 09:41:06 CEST 2017


Still failed. 

The first secret is in your email program settings, to use Plain Text format (at least for emails you send to this mailing list).

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[1] http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example

[2] http://adv-r.had.co.nz/Reproducibility.html

[3] https://cran.r-project.org/web/packages/reprex/index.html (read the vignette) 
-- 
Sent from my phone. Please excuse my brevity.

On September 23, 2017 9:53:05 PM PDT, array chip via R-help <r-help at r-project.org> wrote:
>Sorry for messed up text. Here it goes again:
>I am learning to use the gsDesign package.
>I have a question about Pocock and OBF boundary. As far as I can
>understand, these 2 boundaries require equal spacing between interim
>analyses (maybe this is not correct?). But looks like I can still use
>gsDesign to run an analysis based on unequal spacing: 
>> gsDesign(k=2,test.type=2,timing=c(0.75,1),alpha=0.05,sfu='Pocock')
>Symmetric two-sided group sequential design with 90 %power and 5 % Type
>I Error.Spending computations assume trial stops if a bound is
>crossed.          Sample          Size  Analysis Ratio*  Z  Nominal p 
>Spend        1  0.796 1.82    0.0346 0.0346        2  1.061 1.82   
>0.0346 0.0154    Total                      0.0500 ++alpha spending:
>Pocock boundary.*Sample size ratio compared to fixed design with no
>interim 
>Can anyone share some light whether the above analysis is still valid?
>Or for unequal spacing, I have to use Lan-Demet’s error spending
>function approximations? Thank you,
>
>
>
>      From: Berend Hasselman <bhh at xs4all.nl>
> To: array chip <arrayprofile at yahoo.com> 
>Cc: R-help Mailing List <r-help at r-project.org>
> Sent: Friday, September 22, 2017 11:46 PM
> Subject: Re: [R] gsDesign Pocock & OBF boundary
>   
>
>> On 23 Sep 2017, at 01:32, array chip via R-help
><r-help at r-project.org> wrote:
>> 
>> Hi, 
>> 
>> I am learning to use your gsDesign package! I have a question about
>Pocock and OBF boundary. As far as Iunderstand, these 2 boundaries
>require equal spacing between interim analyses(maybe this is not
>correct?). But I can still use gsDesign to run an analysisbased on
>unequal spacing:
>gsDesign(k=2,test.type=2,timing=c(0.75,1),alpha=0.05,sfu='Pocock')Symmetrictwo-sided
>group sequential design with90 %power and 5 % Type I
>Error.Spendingcomputations assume trial stops if a bound is crossed.   
>      Sample          Size  AnalysisRatio*  Z  Nominal p  Spend       
>1  0.796 1.82    0.0346 0.0346        2  1.061 1.82    0.0346 0.0154   
>Total                      0.0500  ++alpha
>spending:Pocockboundary.*Sample size ratio compared to fixed design
>with no interim Can anyone share some light whether the above analysis
>is stillvalid? Or for unequal spacing, I have to use Lan-Demet’s error
>spendingfunction approximations? Thank you,
>>     [[alternative HTML version deleted]]
>> 
>
>Your example code is a complete mess.
>Do NOT post in html. This is a plain text mailing list.
>Read the Posting Guide (https://www.r-project.org/posting-guide.html).
>
>Berend Hasselman]
>
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
>
>   
>	[[alternative HTML version deleted]]
>
>______________________________________________
>R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>https://stat.ethz.ch/mailman/listinfo/r-help
>PLEASE do read the posting guide
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>and provide commented, minimal, self-contained, reproducible code.



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