create_jaatha_stat: Create a summary statistic for Jaatha
Description
This function creates summary statistics for Jaatha models. A summary
statistic consists primarily of a function that calculates the statistic
from the simulation results. Jaatha primarily supports Poisson distributed
summary statistics, but can also transform summary statistics that follow
a different distribution in approximately Poisson distributed statistics.Usage
create_jaatha_stat(name, calc_func, poisson = TRUE, breaks = c(0.1, 0.5,
0.9))
Arguments
name
The name of the summary statistic
calc_func
The function that summarizes the simulation data. Must take
two arguments. The first is the simulated data, and the second are
options that can be calculated from the real data. Ignoring the second
argument in the function body should be fine in most sit
poisson
If TRUE, it is assumed that the summary statistic
values are (at least approximately) independent and Poisson distributed.
If it is set to FALSE, the statistic is transformed into an approximately
Poisson distributed array using
breaks
The probabilities for the quantiles that are used for binning
the data. See the section on non Poisson distributed summary statistics
for details.
Transformation of non Poisson distributed statistics
To transform a statistic into approximately Poisson distributed values,
we first calculate the empirical quantiles of the real data for the
probabilities given in breaks. These are used as break points for
divining the range of the statistic into disjunct intervals. We then count
who many of the values for the simulated data fall into each intervals, and
use this counts as summary statistic. The counts are multinomial
distributed, and should be close to the required Poisson distribution in
most cases.