On 4/14/2008 6:35 AM, Chuck Cleland wrote:
> On 4/14/2008 6:21 AM, Louisa Hay wrote:
>>
>> Hi,
>> I am trying to create a power curve to show how the power of a t-test varies
>> depending on the mean. Any ideas how I should go about this?
>> Louisa
>
> Something like this maybe?
>
> mydiffs <- seq(.05,1,.05)
>
> mypower <- vector("numeric", 20)
>
> for(i in 1:20){
> mypower[i] <- power.t.test(n=100, sd=1, delta=mydiffs[i])$power
> }
>
> plot(mymeans, mypower, xlab="delta", ylab="Power", type="b")
Sorry - that last line should be:
plot(mydiffs, mypower, xlab="delta", ylab="Power", type="b")
> See ?power.t.test
>
>> _________________________________________________________________
>>
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--
Chuck Cleland, Ph.D.
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