This dialog provides rudimentary power analysis for an
exact test of a Poisson parameter.  Specifically, our data
are assumed to be x_1, x_2, ..., x_n iid Poisson(lambda),
so that x = sum{x_i} is Poisson with mean n*lambda serves
as the test statistic.  The critical value(s) for x are
obtained using quantiles of the null Poisson distribution
so as to cut off tail(s) of probability less than or equal
to alpha.  The power of the test is then the probability
of the critical region, computed from a Poisson
distribution with the specified value of lambda.

The GUI components are as follows:

lambda0: The value of the Poisson parameter under the
null hypothesis.

alternative: Choose a two-tailed alternative (lambda != 
lambda0) or one of the one-tailed alternatives.

Boundaries of acceptance region (output values):  These
are the lower and/or upper values of x for which the null
hypothesis would NOT be rejected.

size (output value):  The actual probability of the
critical region under the null hypothesis.

lambda: The Poisson parameter at which the power is to be
calculated.

n: The sample size.

power: The probability of the critical region, given lambda and n.
