st: RE: RE: generate graph (try 2)

["Philip Ryan" <philip.ryan@adelaide.edu.au>]

<<>> 

For reasons not clear to me, the return from my own initial posting seemed
to have left out some carriage returns that were present in what I sent.
Perhaps this, inserting several double carriage returns, will be better. (Of
course, code should be run from the do file editor).

*==== begin code ====*

clear
tempname temp_ss
local sd .75
local pow 0.8
local m1 0.35
local m2 0

quietly {

postfile `temp_ss'  sample_size  alpha  using  my_ss, replace

forvalues alpha = .01(.01).2{

sampsi `m1'  `m2', alpha(`alpha')  power(`pow') sd(`sd')  r(1) 

post `temp_ss' (r(N_1)) (`alpha') 

} 

postclose `temp_ss'

} 

/* now make use of our new data set */

use my_ss
list, clean abbrev(16)
graph twoway line  sample_size alpha,  ///  ytitle("sample size in each
group") xlabel(0(.01).2) ///
 lwidth(medthick) lcolor(blue)

*=== end code ===



Philip Ryan
Professor and Director
Data Management & Analysis Centre
School of Population Health & Clinical Practice
University of Adelaide

Postal address:
DMAC
Mail Drop DX650 511
University of Adelaide 5005
South Australia
Australia

location:
Level 6
Bice Building
Royal Adelaide Hospital
North Terrace
Adelaide SA

tel: +61 (0)8  83033570
fax: +61 (0)8 82234075


-----Original Message-----
From: owner-statalist@hsphsun2.harvard.edu
[mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Philip Ryan
Sent: Thursday, 3 November 2011 6:04 PM
To: statalist@hsphsun2.harvard.edu
Subject: st: RE: generate graph

<<>>

Something like this (grafting onto -sampsi-) ?:

*==== begin code ====*

clear
tempname temp_ss
local sd .75
local pow 0.8
local m1 0.35
local m2 0

quietly {
postfile `temp_ss'  sample_size  alpha  using  my_ss, replace

forvalues alpha = .01(.01).2{
sampsi `m1'  `m2', alpha(`alpha')  power(`pow') sd(`sd')  r(1)
post `temp_ss' (r(N_1)) (`alpha')
} 

postclose `temp_ss'

} 

/* now make use of our new data set */

use my_ss
list, clean abbrev(16)
graph twoway line  sample_size alpha,  ///
 ytitle("sample size in each group") xlabel(0(.01).2) ///
 lwidth(medthick) lcolor(blue)

*=== end code ===


Philip Ryan


-----Original Message-----
From: owner-statalist@hsphsun2.harvard.edu
[mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Nikolaos Pandis
Sent: Thursday, 3 November 2011 5:34 PM
To: statalist@hsphsun2.harvard.edu
Subject: st: generate graph

Hi to all.
 
I was wondering if someone could help me generate the following graph:
 
twoway line graph showing on the y-axis: sample size and on the x-axis:
p-value.
 
The objective is to show how the p-value decreases (increases) as the sample
size increases (decreases) given the same effect size and sd
 
Many thanks,
 
Nick

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