Yes my mistake, I looked at the pwr.2p2n.test but i cannot place both n's and both p values to determine the sig value e,g *pwr.2p2n.test(h = , n1 = , n2 = , sig.level = , power = )
or am i missing someting obvious? i did the sam ein SPSS using a macro and the following code: COMPUTE n1 = Control_MAX . COMPUTE n2 = Exposed_max. COMPUTE x1 = Control. COMPUTE x2 = Exposed. COMPUTE p1 = x1/n1. COMPUTE p2 = x2/n2. COMPUTE phat = (x1 + x2) / (n1 + n2). COMPUTE SE_phat = SQRT(phat * (1 - phat) * ((1/n1) + (1/n2))). COMPUTE z = (p1 - p2) /SE_phat. COMPUTE SIGz_2TL = 2 * (1 - CDFNORM(ABS(z))). COMPUTE SIGz_LTL = CDFNORM(Z). COMPUTE SIGz_UTL = 1 - CDFNORM(Z). COMPUTE SIG_Level = ABS(1-(1-CDFNORM(z))*2). Compute p1p = p1*100. Compute p2p = p2*100. compute diff = p2p-p1p. EXE. Var lab p1p "Control Group %". Var lab p2p "Exposed Group %". * On Tue, Jun 17, 2008 at 5:13 PM, Peter Dalgaard <[EMAIL PROTECTED]> wrote: > Michael Pearmain wrote: > > Hi All, > > > > I have a table based on ordial data and i want to compare proportions and > > i've seen in the pwr package i can use > > power.prop.test > > > > however i want to find out what the sig. value is based on n1,n2,p1,p2 > and > > this package doesn't contain this.. > > Does anyone know of a package that does or is it a case of writting a > > function specifically for this? > > > > > I think your wired got crossed somewhere: > > power.prop.test is not from the pwr package; however, pwr does contain > pwr.2p2n.test, which looks like it does exactly what you want! > > > > Many thanks in advance > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > 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. > > > > > -- > O__ ---- Peter Dalgaard Øster Farimagsgade 5, Entr.B > c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K > (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 > ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 > > > -- Michael Pearmain Senior Statistical Analyst 1st Floor, 180 Great Portland St. London W1W 5QZ t +44 (0) 2032191684 [EMAIL PROTECTED] [EMAIL PROTECTED] Doubleclick is a part of the Google group of companies [[alternative HTML version deleted]]
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