set_pars: Set the parameters to the desired values.

View source: R/Schistox.R

set_parsR Documentation

Set the parameters to the desired values.

Description

Set the parameters to the desired values.

Usage

set_pars(
  N,
  time_step,
  N_communities,
  community_probs,
  community_contact_rate,
  density_dependent_fecundity,
  average_worm_lifespan,
  max_age,
  initial_worms,
  initial_miracidia,
  initial_miracidia_days,
  init_env_cercariae,
  worm_stages,
  contact_rate,
  max_fec_contact_rate_product,
  max_fecundity,
  age_contact_rates,
  ages_for_contacts,
  contact_rate_by_age_array,
  mda_adherence,
  mda_access,
  female_factor,
  male_factor,
  miracidia_maturity,
  birth_rate,
  human_cercariae_prop,
  predis_aggregation,
  cercariae_survival,
  miracidia_survival,
  death_prob_by_age,
  ages_for_death,
  r,
  vaccine_effectiveness,
  drug_effectiveness,
  spec_ages,
  ages_per_index,
  record_frequency,
  use_kato_katz,
  kato_katz_par,
  heavy_burden_threshold,
  rate_acquired_immunity,
  M0,
  human_larvae_maturity_time,
  egg_sample_size,
  egg_production_distribution,
  input_ages,
  input_contact_rates,
  scenario
)

Arguments

N

size of human population (Int)

time_step

length of time in days to step forward each time (Float)

N_communities

number of communities sharing the same environmental source (Int)

community_probs

probability of an integer being in a given community. This governs the population sizes in each community. This must be an array the length of N_communities (Array(Float))

community_contact_rate

contact rate with the environment for each of the communities. This must be an array the length of N_communities (Array(Float))

density_dependent_fecundity

decrease in egg production per worm due to high density of worms (Float)

average_worm_lifespan

average life expectancy of a worm (Float)

max_age

maximum age of human in the population (Float)

initial_worms

number of worms in each person to begin with. The actual number in each person if chosen from a Poisson distirubiton with this mean (Int)

initial_miracidia

initial number of miracidia larvae in the environment (Int)

initial_miracidia_days

miracidia will age into cercariae larvae after a specified number of days. This parameter will specify how many days of initial_miracidia we will have already had in the environment (Int)

init_env_cercariae

initial number of cercariae larvae in the environment (Int)

worm_stages

how many age stages are there for the worms. Having 1 stage will give Gamma distributed death ages, while more than 1 will result in Erlang distribution (Int)

contact_rate

global contact rate for the uptake of larvae from the environment (Float)

max_fec_contact_rate_product

the product of max fecundity and the contact rate in the population. Setting this to a desired value is often a good way to ensure that the epidemic stays within a reasonable range, as when the max fecundity increases, if the contact rate doesn't decrease appropriately, then the behaviour of the outbreak can be unrealistically difficult to control. Contact rate can then be calculate by dividing this value by max fecundity or vice versa. (Float)

max_fecundity

expected number of eggs from a single worm pair. The actual number will be chosen from a distribution with this mean (Float)

age_contact_rates

contact rate for chosen age groups(Array(Float))

ages_for_contacts

age groups for specifying contact rates (Array(Int))

contact_rate_by_age_array

array holding contact rate for each age (Array(Float))

mda_adherence

proportion of people who adhere to the mda (Float)

mda_access

proportion of people who have access to the mda (Float)

female_factor

factor for altering the contact rate for females, if we choose to have gender specific behaviour which affects contact rate (Float)

male_factor

factor for altering the contact rate for males, if we choose to have gender specific behaviour which affects contact rate (Float)

miracidia_maturity

number of days after which miracidias will mature to cercariae (Int)

birth_rate

rate of birth of humans (Float)

human_cercariae_prop

proportion of cercariae which are able to infect humans (Float)

predis_aggregation

aggregation for predisposition of individuals to uptake larvae. This is chosen from a Gamma distribution with mean 1 for each individual and set for life. If this is high, then the aggregation is low, meaning that most individuals have roughly the same predisposition. If it is low, then the larvae become concentrated in a few individuals. (Float)

cercariae_survival

what proportion of cercariae survive from one time point to the next (Float)

miracidia_survival

what proportion of miracidia survive from one time point to the next (Float)

death_prob_by_age

for specified age range, what is the probability of dying each year (Array(Float))

ages_for_death

age ranges for death probabilities (Array(Float))

r

aggregation parameter for negative binomially distributed egg production (Float)

vaccine_effectiveness

efficacy of a vaccine if one is used(Float)

drug_effectiveness

efficacy of a drug given during MDA(Float)

spec_ages

number of individuals by age group which we specify if we want a particular age distribution for the simulation (Array(Float))

ages_per_index

how many different ages we include in the spec_ages parameter (Int)

record_frequency

how often we should record the prevalence in the population during simulation (Float)

use_kato_katz

if 0, then don't use Kato-Katz (KK) for egg counts, if 1, use KK (Int)

kato_katz_par

parameter for Gamma distribution if KK is used (Float)

heavy_burden_threshold

number of eggs at which an individual is said to have a heavy infection (Int)

rate_acquired_immunity

rate at which immunity will be acquired for individuals. This will be multiplied by the cumulative number of worms people have had throughout their life to decide the level of immunity acquired (Float)

M0

if a particular for of egg production is used, this parameter is required and is a proxy for mean worm burden (Float)

human_larvae_maturity_time

length of time in days after which a cercariae uptaken by a human will mature into a worm (Int)

egg_sample_size

the proportion of eggs which are sampled from each individual every time we check their burden. This is between 0 and 1, with 1 meaning that all the eggs in the person are sampled, hence giving the true burden. Typical value for a urine sample may be ~ 1/100

egg_production_distribution

the distribution for egg production. Must be either "Poisson" or "NegBin"

input_ages

input ages for constructing contact array

input_contact_rates

input rates for constructing contact array

scenario

can be one of "low adult", "moderate adult", "high adult"


mattg3004/SchistoxpkgR documentation built on March 1, 2023, 10:46 a.m.