pref_sample: Sample preferentially
In mdkarcher/phylodyn: Statistical Tools for Phylodynamics

Sample values from an inhomogeneous Poisson process with intensity c*f(t)^beta.

1 2	pref_sample(f, lim = c(0, 1), c = 1, beta = 1, upper = NULL, grid.len = 1000)

`f`	function to be sampled from preferentially.
`lim`	lower and upper sampling bounds. Defaults to c(0,1).
`c`	numeric constant of proportionality for intensity. Defaults to 1.
`beta`	numeric power to which f is raised for intensity. Defaults to 1.
`upper`	numeric upper bound for function between limits defined by lim. Used in thinning algorithm.
`grid.len`	integer if upper is undefined, automatically evaluates f at grid.len points between min(lim) and max(lim) to find upper bound.