power.z.test {asbio} | R Documentation |
A power analysis for a one sample z-test. The function requires α, σ, the effect size, the type of test (one tailed or two-tailed), and either power (1 - β) or n (sample size). If n is provided, then power is calculated. Conversely, if one provides power, but not n, then the required n is calculated.
power.z.test(sigma = 1, n = NULL, power = NULL, alpha = 0.05, effect = NULL, test = c("two.tail", "one.tail"), strict = FALSE)
sigma |
The population standard deviation. |
n |
The sample size. Not required if |
power |
The desired power. Not required if |
alpha |
Probability of type I error. |
effect |
Effect size. |
test |
One of two choices: |
strict |
Causes the function to use a strict interpretation of power in a two-sided test.
If |
Returns a list
sigma |
The prescribed population variance. |
n |
The sample size. |
power |
The power. |
alpha |
The type I error probability. |
test |
The type of test prescribed. |
effect |
The effect size. |
Ken Aho
Bain, L. J., and M. Engelhardt (1992) Introduction to Probability and Mathematical Statistics. Duxbury press. Belmont, CA, USA.
power.z.test(sigma=6,effect=5,power=.9,test="one.tail")