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    Paired longitudinal analysis

    Hello all, I need your advice. I am examining an new eye drops. In order to examine, an experiment was performed, in which a subject was enrolled, and one eye was randomized to get the drops, while the other was the control. Before giving the drops, some quantitative measure was taken on...
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    Proc mixed

    Hello all, I am a wee bit confused about the random statement in PROC MIXED, I thought maybe you can clarify it for me in simple words. Let's for the illustration say I have an outcome variable Y, and a treatment variable X, getting: 1 - New intervention 0 - Control (or placebo in...
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    Power of a one sample t-test

    Hi all, I have a little problem with power calculations. I have calculated the power for a one sample Z test, which was fine. I found the critical value under H0: X_{a}=M_{0} plus+ Z_{\alpha }\cdot \frac{\sigma }{\sqrt{n}} then I calculated the Z value under a specific value for H1, and...
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    Power of t-test

    Hello all, I want to write an R procedure that calculates the power of a simple two samples t-test. Does anyone here has an idea how to do it ? Thank you !