Re: [R] gsDesign Pocock & OBF boundary

2017-09-24 Thread array chip via R-help 
Sorry it didn 't work again. I am on yahoo mail, and just found a switch to 
change from Rick text to Plain text, so 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: 

> library(gsDesign)
> 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: Jeff Newmiller <jdnew...@dcn.davis.ca.us>

oject.org>; Berend Hasselman <b...@xs4all.nl> 
Cc: R-help Mailing List <r-help@r-project.org>
Sent: Sunday, September 24, 2017 12:41 AM
Subject: Re: [R] gsDesign Pocock & OBF boundary



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).

The second secret tool to use is the reprex package to let you verify that your 
code example will do on our computers what it is doing on your computer before 
you send it to us. That will also involve giving us some sample data or 
referencing some data already available to us in a relevant package. See [1], 
[2] and [3] for more discussion of how to succeed at communicating on the 
Internet regarding R. 

[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@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 
>Spend1  0.796 1.820.0346 0.03462  1.061 1.82   
>0.0346 0.0154Total  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 <b...@xs4all.nl>

>Cc: R-help Mailing List <r-help@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@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 1.820.0346 0.03462  1.061 1.820.0346 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 pl

Re: [R] gsDesign Pocock & OBF boundary

2017-09-24 Thread Jeff Newmiller 
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).

The second secret tool to use is the reprex package to let you verify that your 
code example will do on our computers what it is doing on your computer before 
you send it to us. That will also involve giving us some sample data or 
referencing some data already available to us in a relevant package. See [1], 
[2] and [3] for more discussion of how to succeed at communicating on the 
Internet regarding R. 

[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@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 <b...@xs4all.nl>
> To: array chip <arrayprof...@yahoo.com> 
>Cc: R-help Mailing List <r-help@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@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@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@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.

__
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Re: [R] gsDesign Pocock & OBF boundary

2017-09-23 Thread array chip via R-help 
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 <b...@xs4all.nl>
 To: array chip <arrayprof...@yahoo.com> 
Cc: R-help Mailing List <r-help@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@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@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@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.

Re: [R] gsDesign Pocock & OBF boundary

2017-09-23 Thread Berend Hasselman 

> On 23 Sep 2017, at 01:32, array chip via R-help  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  Spend1  0.796 
> 1.820.0346 0.03462  1.061 1.820.0346 0.0154Total  
> 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@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.

__
R-help@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.

[R] gsDesign Pocock & OBF boundary

2017-09-23 Thread array chip via R-help 
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  Spend1  0.796 
1.82    0.0346 0.03462  1.061 1.82    0.0346 0.0154Total
  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]]

__
R-help@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.

Re: [R] gsDesign

2011-11-15 Thread Liaw, Andy 
Hi Dongli,

Questions about usage of specific contributed packages are best directed toward 
the package maintainer/author first, as they are likely the best sources of 
information, and they don't necessarily subscribe to or keep up with the daily 
deluge of R-help messages.

(In this particular case, I'm quite sure the package maintainer for gsDesign 
doesn't keep up with R-help.)

Best,
Andy
 

 -Original Message-
 From: r-help-boun...@r-project.org 
 [mailto:r-help-boun...@r-project.org] On Behalf Of Dongli Zhou
 Sent: Monday, November 14, 2011 6:13 PM
 To: Marc Schwartz
 Cc: r-help@r-project.org
 Subject: Re: [R] gsDesign
 
 Hi, Marc,
 
 Thank you very much for the reply. I'm using the gsDesign 
 function to create an object of type gsDesign. But the inputs 
 do not include the 'ratio' argument.
 
 Dongli 
 
 On Nov 14, 2011, at 5:50 PM, Marc Schwartz 
 marc_schwa...@me.com wrote:
 
  On Nov 14, 2011, at 4:11 PM, Dongli Zhou wrote:
  
  I'm trying to use gsDesign for a noninferiority trial with binary
  endpoint. Did anyone know how to specify the trial with 
 different sample
  sizes for two treatment groups? Thanks in advance!
  
  
  Hi,
  
  Presuming that you are using the nBinomial() function, see 
 the 'ratio' argument, which defines the desired sample size 
 ratio between the two groups.
  
  See ?nBinomial and the examples there, which does include 
 one using the 'ratio' argument.
  
  HTH,
  
  Marc Schwartz
  
 
 __
 R-help@r-project.org mailing list
 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.
 
Notice:  This e-mail message, together with any attachme...{{dropped:11}}

__
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Re: [R] gsDesign

2011-11-15 Thread Marc Schwartz 
Hi Dongli,

Sorry for the delay in following up.

You might want to read the dsDesignManual.pdf document, which is available in 
the 'inst/doc' folder in the package source tarball on CRAN, or in the package 
'doc' directory in your R installation. Use:

  system.file(package = gsDesign)

to get the package top directory for your installation. The above file will be 
in the 'doc' sub-directory from there. It has more extensive worked examples 
than the default package manual.


Simple non-inferiority example from ?nBinomial, with 2:1 ratio:

n.Fix - nBinomial(p1 = .677, p2 = .677, delta0 = 0.07, ratio = 2)


 n.Fix
[1] 2056.671

# Adjust that *up* to an integer multiple of 3
n.Fix - 2058


# Change 'outtype' to 2 if you want to see per arm sample sizes
# eg:
 nBinomial(p1 = .677, p2 = .677, delta0 = 0.07, ratio = 2, outtype = 2)
$n1
[1] 685.5569

$n2
[1] 1371.114




# Simple default GS design using the fixed study design sample size from above, 
# which is not yet adjusted for interim analyses

 gsDesign(n.fix = n.Fix)
Asymmetric two-sided group sequential design with
90 % power and 2.5 % Type I Error.
Upper bound spending computations assume
trial continues if lower bound is crossed.

  Lower bounds  Upper bounds-
  Analysis   NZ   Nominal p Spend+  Z   Nominal p Spend++
 1  734 -0.240.4057 0.0148 3.010.0013  0.0013
 2 1468  0.940.8267 0.0289 2.550.0054  0.0049
 3 2202  2.000.9772 0.0563 2.000.0228  0.0188
 Total  0.1000 0.0250 
+ lower bound beta spending (under H1):
 Hwang-Shih-DeCani spending function with gamma = -2
++ alpha spending:
 Hwang-Shih-DeCani spending function with gamma = -4

Boundary crossing probabilities and expected sample size
assume any cross stops the trial

Upper boundary (power or Type I Error)
  Analysis
   Theta  1  2  3  Total   E{N}
  0. 0.0013 0.0049 0.0171 0.0233 1286.0
  0.0715 0.1412 0.4403 0.3185 0.9000 1628.4

Lower boundary (futility or Type II Error)
  Analysis
   Theta  1  2  3  Total
  0. 0.4057 0.4290 0.1420 0.9767
  0.0715 0.0148 0.0289 0.0563 0.1000


So rather than needing 2058 from the fixed design, you actually need 2202 (1468 
in one arm and 734 in the other).

I would urge you to read the manual I reference above and as Andy has noted in 
his reply, contact Keaven directly for further assistance with this package.

HTH,

Marc

On Nov 14, 2011, at 5:13 PM, Dongli Zhou wrote:

 Hi, Marc,
 
 Thank you very much for the reply. I'm using the gsDesign function to create 
 an object of type gsDesign. But the inputs do not include the 'ratio' 
 argument.
 
 Dongli 
 
 On Nov 14, 2011, at 5:50 PM, Marc Schwartz marc_schwa...@me.com wrote:
 
 On Nov 14, 2011, at 4:11 PM, Dongli Zhou wrote:
 
 I'm trying to use gsDesign for a noninferiority trial with binary
 endpoint. Did anyone know how to specify the trial with different sample
 sizes for two treatment groups? Thanks in advance!
 
 
 Hi,
 
 Presuming that you are using the nBinomial() function, see the 'ratio' 
 argument, which defines the desired sample size ratio between the two groups.
 
 See ?nBinomial and the examples there, which does include one using the 
 'ratio' argument.
 
 HTH,
 
 Marc Schwartz


__
R-help@r-project.org mailing list
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.

Re: [R] gsDesign

2011-11-15 Thread Dongli Zhou 
Thank you so much for the help! It is really appreciated!

Dongli

On Nov 15, 2011, at 9:19 AM, Marc Schwartz marc_schwa...@me.com wrote:

 Hi Dongli,
 
 Sorry for the delay in following up.
 
 You might want to read the dsDesignManual.pdf document, which is available in 
 the 'inst/doc' folder in the package source tarball on CRAN, or in the 
 package 'doc' directory in your R installation. Use:
 
  system.file(package = gsDesign)
 
 to get the package top directory for your installation. The above file will 
 be in the 'doc' sub-directory from there. It has more extensive worked 
 examples than the default package manual.
 
 
 Simple non-inferiority example from ?nBinomial, with 2:1 ratio:
 
 n.Fix - nBinomial(p1 = .677, p2 = .677, delta0 = 0.07, ratio = 2)
 
 
 n.Fix
 [1] 2056.671
 
 # Adjust that *up* to an integer multiple of 3
 n.Fix - 2058
 
 
 # Change 'outtype' to 2 if you want to see per arm sample sizes
 # eg:
 nBinomial(p1 = .677, p2 = .677, delta0 = 0.07, ratio = 2, outtype = 2)
 $n1
 [1] 685.5569
 
 $n2
 [1] 1371.114
 
 
 
 
 # Simple default GS design using the fixed study design sample size from 
 above, 
 # which is not yet adjusted for interim analyses
 
 gsDesign(n.fix = n.Fix)
 Asymmetric two-sided group sequential design with
 90 % power and 2.5 % Type I Error.
 Upper bound spending computations assume
 trial continues if lower bound is crossed.
 
  Lower bounds  Upper bounds-
  Analysis   NZ   Nominal p Spend+  Z   Nominal p Spend++
 1  734 -0.240.4057 0.0148 3.010.0013  0.0013
 2 1468  0.940.8267 0.0289 2.550.0054  0.0049
 3 2202  2.000.9772 0.0563 2.000.0228  0.0188
 Total  0.1000 0.0250 
 + lower bound beta spending (under H1):
 Hwang-Shih-DeCani spending function with gamma = -2
 ++ alpha spending:
 Hwang-Shih-DeCani spending function with gamma = -4
 
 Boundary crossing probabilities and expected sample size
 assume any cross stops the trial
 
 Upper boundary (power or Type I Error)
  Analysis
   Theta  1  2  3  Total   E{N}
  0. 0.0013 0.0049 0.0171 0.0233 1286.0
  0.0715 0.1412 0.4403 0.3185 0.9000 1628.4
 
 Lower boundary (futility or Type II Error)
  Analysis
   Theta  1  2  3  Total
  0. 0.4057 0.4290 0.1420 0.9767
  0.0715 0.0148 0.0289 0.0563 0.1000
 
 
 So rather than needing 2058 from the fixed design, you actually need 2202 
 (1468 in one arm and 734 in the other).
 
 I would urge you to read the manual I reference above and as Andy has noted 
 in his reply, contact Keaven directly for further assistance with this 
 package.
 
 HTH,
 
 Marc
 
 On Nov 14, 2011, at 5:13 PM, Dongli Zhou wrote:
 
 Hi, Marc,
 
 Thank you very much for the reply. I'm using the gsDesign function to create 
 an object of type gsDesign. But the inputs do not include the 'ratio' 
 argument.
 
 Dongli 
 
 On Nov 14, 2011, at 5:50 PM, Marc Schwartz marc_schwa...@me.com wrote:
 
 On Nov 14, 2011, at 4:11 PM, Dongli Zhou wrote:
 
 I'm trying to use gsDesign for a noninferiority trial with binary
 endpoint. Did anyone know how to specify the trial with different sample
 sizes for two treatment groups? Thanks in advance!
 
 
 Hi,
 
 Presuming that you are using the nBinomial() function, see the 'ratio' 
 argument, which defines the desired sample size ratio between the two 
 groups.
 
 See ?nBinomial and the examples there, which does include one using the 
 'ratio' argument.
 
 HTH,
 
 Marc Schwartz
 
 

__
R-help@r-project.org mailing list
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.

[R] gsDesign

2011-11-14 Thread Dongli Zhou 
 I'm trying to use gsDesign for a noninferiority trial with binary
endpoint. Did anyone know how to specify the trial with different sample
sizes for two treatment groups? Thanks in advance!

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Re: [R] gsDesign

2011-11-14 Thread Marc Schwartz 
On Nov 14, 2011, at 4:11 PM, Dongli Zhou wrote:

 I'm trying to use gsDesign for a noninferiority trial with binary
 endpoint. Did anyone know how to specify the trial with different sample
 sizes for two treatment groups? Thanks in advance!


Hi,

Presuming that you are using the nBinomial() function, see the 'ratio' 
argument, which defines the desired sample size ratio between the two groups.

See ?nBinomial and the examples there, which does include one using the 'ratio' 
argument.

HTH,

Marc Schwartz

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Re: [R] gsDesign

2011-11-14 Thread Dongli Zhou 
Hi, Marc,

Thank you very much for the reply. I'm using the gsDesign function to create an 
object of type gsDesign. But the inputs do not include the 'ratio' argument.

Dongli 

On Nov 14, 2011, at 5:50 PM, Marc Schwartz marc_schwa...@me.com wrote:

 On Nov 14, 2011, at 4:11 PM, Dongli Zhou wrote:
 
 I'm trying to use gsDesign for a noninferiority trial with binary
 endpoint. Did anyone know how to specify the trial with different sample
 sizes for two treatment groups? Thanks in advance!
 
 
 Hi,
 
 Presuming that you are using the nBinomial() function, see the 'ratio' 
 argument, which defines the desired sample size ratio between the two groups.
 
 See ?nBinomial and the examples there, which does include one using the 
 'ratio' argument.
 
 HTH,
 
 Marc Schwartz
 

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and provide commented, minimal, self-contained, reproducible code.