Dear list
i have written the following program in order to calculate the sample size
(i want to advance on it which is why i didnt use sampsi) but it returns an
error message and I can't spot the error at present.
program define sampsi1
version 7.0
syntax [, ZAlpha (real 1.645) ZPower (real 0.8416) HRatio (real 1.5) CEnsor
(real 0.8) PControl (real 0.5)]
if "`ZAlpha'"==" {
ret local errmess "zalpha required"
exit 198
}
if `zalpha'<=0 {
ret local errmess "zalpha() out of range"
exit 198
}
if "`zpower'"==" {
ret local errmess "zpower required"
exit 198
}
if `zpower'<=0 {
ret local errmess "zpower() out of range"
exit 198
}
if "`hratio'"==" {
ret local errmess "hratio required"
exit 198
}
if `hratio' <= 0 {
ret local errmess "hratio out of range"
exit 198
}
if "`censor'"==" {
ret local errmess "censor required"
exit 198
}
if `censor'<=0 | `censor'>=1 {
ret local errmess "censor out of range"
exit 198
}
if "`pcontrol'"==" {
ret local errmess "pcontrol needed"
exit 198
}
if `pcontrol'<=0 | `pcontrol'>=1 {
ret local errmess "pcontrol out of range"
exit 198
}
tempname N0 N1 N2 N
scalar `N0' = (`ZAlpha'+`ZPower')^2
scalar `N1'=(log(`HRatio'))^2
scalar `N2'=`CEnsor'*`PControl'*(1-`PControl')
scalar `N'=`N0'/(`N1'*`N2')
return N=`N'
end
exit
Thank you for your help
Sophie
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