RSPS (version 1.0)

poiss.pow: Estimates power for given sample size using simulation from Poisson distribution

Description

The function provides estimate of power for given sample size when there is no over-dispersion. The data is simulated from Poisson distribution.

Usage

poiss.pow(n, lambda1, k, alpha = 0.05, seed = 20, numsim = 2000, monitor = TRUE, sig = 3)

Arguments

n

A vector of positive integers representing the sample size

lambda1

Mean count under the null distribution. It can be a vector.

k

Fold change desired under the alternative distribution. It can be a vector.

alpha

Type I error rate: a value between 0 and 1. It can be a vector.

seed

Value of seed to ensure reproducibility of results.

numsim

Number of simulations. 1000 is recommended.

monitor

If TRUE, it allows us to view the progress of the function.

sig

Number of significant digits after decimal.

Value

Mean.Null

Mean Count under Null distribution.

Effect.Size

Fold Change Under the alternate hypothesis.

Power

Estimated Power.

Std.Err

Standard Error.

Details

The test statistic used is the scaled difference. Please contact the authors for more details on algorithm.

References

None

See Also

rpois

Examples

#--------------------------------------------------
power.poiss <- poiss.pow(n=c(5,10,15),lambda1=c(3),k=c(2,3),
alpha=0.001,seed = 20,numsim=100,monitor=TRUE)
power.poiss
# Another example (takes longer to run)
#power.poiss <- poiss.pow(n=c(3,5,10,15),lambda1=c(3),k=c(2,2.5,3),
#alpha=0.001,seed = 20,numsim=1000,monitor=TRUE)
#power.poiss