draw_contact_rate: Assign physical distancing behaviour to new cases

In bcgov/epi.branch.sim: Simulates an Epidemic Outbreak with a Branching Process

Description

Distancing behaviour is defined as a number between 0 and 1, representing the relative number of contacts the subject encounters (i.e. 0.6 means the subject reduces contact to 60% of the non-distancing population.)

Usage

draw_contact_rate(n_cases, sim_params, sim_status)

Arguments

n_cases	Number of cases required
sim_params	sim_params object (a list) containing simulation parameters. Here, the sim_params$phys_dist_params object contains the information needed. This list should have the following entries: pd_pop_frac: A number for the fraction of the general population that is practicing distancing. Set this to 0 or 1 to have everyone act the same. pd_contact_rate1: The contact rate of the distancing population before time pd_change_t. Set this to 1 to have the distancing population not begin distancing until a later time. pd_contact_rate2: The contact rate of the distancing population after time pd_change_t. Set this to 1 to have the distancing population stop distancing at a certain time. pd_change_t: The simulation time where the distancing population's contact rate changes. Set this to 0 or a very high number to have only one rate.
sim_status	sim_status object (a list) containing simulation state vector

Details

Current implementation assume that either the entire population has the same distancing behaviour or that the population can be divided into two groups: one that is practicing distancing and one that is not. User provides parameters such as the fraction of the general population that is distancing and the relative contact rate of the distancing population. This relative contact rate can change once, at the time point provided by the user.

Note: The ratio of distancers to non-distancers of new cases is not the same as the ratio amongst the general population (user-provided values). This is because new cases do not arise from the general population but from the population that is in contact with others. Therefore, the fraction of distancers being infected would generally be lower than the fraction of distancers in the general population.

Value

A vector of length n for the contact_rate (double)

bcgov/epi.branch.sim documentation built on Dec. 16, 2020, 5:49 a.m.