A_to_X_dist             function to transform the distribution of stays
                        to a fixed point to the distribution of the
                        staying times
X_to_A_dist             Transform a distribution of times of stay to a
                        distribution of staying-time up to observation
                        point under assumption of steady state.
calculate_I             Function to calculate different estimators for
                        I from PPS data.
calculate_I_mixed       Function to calculate incidence from PPS data
                        using a mix of two estimators
calculate_I_rhame       Function to calculate incidence from PPS data
                        using a Rhame-Sudderth like approach with
                        estimates for x.loi and x.los supplied.
calculate_I_smooth      Estimate the incidence based on PPS data using
                        monotone estimators for the distribution of A.
create_dist_vec         Create vector of probabilities for a finite
                        positive discrete distribution
epmf                    Calculate empirical probability mass function
                        for a discrete positive distribution starting
                        at 1
generate_I_fast         Function to simulate PPS and data and calculate
                        a number of estimators
geom_dist_fct           Probability mass function for a geometric
                        distribution shifted by one and resulting
                        expected value 8
length_biased_dist      Calculate length-biased distribution from
                        discrete length-unbiased distribution starting
                        at 1
length_unbiased_mean    Calculate mean of length-unbiased distribution
                        from discrete length-biased distribution
                        starting at 1
monotone_smoother       Calculate a monotone probability mass function
                        estimate using a rearrangement or a Grenander
                        estimator as described in Jankoswski, Wellner,
                        2009 <doi:10.1214/09-EJS526>
pois_dist_fct           Probability mass function for a Poisson
                        distribution shifted by one and resulting
                        expected value 8
prevtoinc               prevtoinc:
simulate_incidence_stats
                        Calculate theoretical values like x.los, x.loi
                        and other characteristics of the patient
                        population
simulate_incidence_stats_fast
                        Function to calculate theoretical value for
                        x.loi and I
simulate_pps_data       Function to simulate PPS data
simulate_pps_fast       Faster method to generate data for PPS with
                        only length of nosocomial infections as output
