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Samples a contact survey

Usage

contact_matrix(
  survey,
  countries = NULL,
  survey.pop = NULL,
  age.limits = NULL,
  filter = NULL,
  counts = FALSE,
  symmetric = FALSE,
  split = FALSE,
  sample.participants = FALSE,
  estimated.participant.age = c("mean", "sample", "missing"),
  estimated.contact.age = c("mean", "sample", "missing"),
  missing.participant.age = c("remove", "keep"),
  missing.contact.age = c("remove", "sample", "keep", "ignore"),
  weights = NULL,
  weigh.dayofweek = FALSE,
  weigh.age = FALSE,
  weight.threshold = NA,
  symmetric.norm.threshold = 2,
  sample.all.age.groups = FALSE,
  sample.participants.max.tries = 1000,
  return.part.weights = FALSE,
  return.demography = NA,
  per.capita = FALSE,
  ...
)

Arguments

survey

a survey() object.

countries

limit to one or more countries; if NULL (default), will use all countries in the survey; these can be given as country names or 2-letter (ISO Alpha-2) country codes.

survey.pop

survey population – either a data frame with columns 'lower.age.limit' and 'population', or a character vector giving the name(s) of a country or countries from the list that can be obtained via wpp_countries; if NULL (default), will use the country populations from the chosen countries, or all countries in the survey if countries is NULL.

age.limits

lower limits of the age groups over which to construct the matrix. If NULL (default), age limits are inferred from participant and contact ages.

filter

any filters to apply to the data, given as list of the form (column=filter_value) - only contacts that have 'filter_value' in 'column' will be considered. If multiple filters are given, they are all applied independently and in the sequence given. Default value is NULL; no filtering performed.

counts

whether to return counts (instead of means).

symmetric

whether to make matrix symmetric, such that \(c_{ij}N_i = c_{ji}N_j\).

split

whether to split the contact matrix into the mean number of contacts, in each age group (split further into the product of the mean number of contacts across the whole population (mean.contacts), a normalisation constant (normalisation) and age-specific variation in contacts (contacts)), multiplied with an assortativity matrix (assortativity) and a population multiplier (demography). For more detail on this, see the "Getting Started" vignette.

sample.participants

whether to sample participants randomly (with replacement); done multiple times this can be used to assess uncertainty in the generated contact matrices. See the "Bootstrapping" section in the vignette for how to do this.

estimated.participant.age

if set to "mean" (default), people whose ages are given as a range (in columns named "..._est_min" and "..._est_max") but not exactly (in a column named "..._exact") will have their age set to the mid-point of the range; if set to "sample", the age will be sampled from the range; if set to "missing", age ranges will be treated as missing

estimated.contact.age

if set to "mean" (default), contacts whose ages are given as a range (in columns named "..._est_min" and "..._est_max") but not exactly (in a column named "..._exact") will have their age set to the mid-point of the range; if set to "sample", the age will be sampled from the range; if set to "missing", age ranges will be treated as missing.

missing.participant.age

if set to "remove" (default), participants without age information are removed; if set to "keep", participants with missing age are kept and will appear in the contact matrix in a row labelled "NA".

missing.contact.age

if set to "remove" (default), participants that have contacts without age information are removed; if set to "sample", contacts without age information are sampled from all the contacts of participants of the same age group; if set to "keep", contacts with missing age are kept and will appear in the contact matrix in a column labelled "NA"; if set to "ignore", contacts without age information are removed from the analysis (but the participants that made them are kept).

weights

column names(s) of the participant data of the survey() object with user-specified weights (default = empty vector).

weigh.dayofweek

whether to weigh social contacts data by the day of the week (weight (5/7 / N_week / N) for weekdays and (2/7 / N_weekend / N) for weekends).

weigh.age

whether to weigh social contacts data by the age of the participants (vs. the populations' age distribution).

weight.threshold

threshold value for the standardized weights before running an additional standardisation (default 'NA' = no cutoff).

symmetric.norm.threshold

threshold value for the normalization weights when symmetric = TRUE before showing a warning that that large differences in the size of the sub-populations are likely to result in artefacts when making the matrix symmetric (default 2).

sample.all.age.groups

what to do if sampling participants (with sample.participants = TRUE) fails to sample participants from one or more age groups; if FALSE (default), corresponding rows will be set to NA, if TRUE the sample will be discarded and a new one taken instead.

sample.participants.max.tries

maximum number of attempts when sample.all.age.groups = TRUE; defaults to 1000.

return.part.weights

boolean to return the participant weights.

return.demography

boolean to explicitly return demography data that corresponds to the survey data (default 'NA' = if demography data is requested by other function parameters).

per.capita

whether to return a matrix with contact rates per capita (default is FALSE and not possible if 'counts=TRUE' or 'split=TRUE').

...

further arguments to pass to get_survey(), check() and pop_age() (especially column names).

Value

a contact matrix, and the underlying demography of the surveyed population

Author

Sebastian Funk

Examples

data(polymod)
contact_matrix(
  survey = polymod,
  countries = "United Kingdom",
  age.limits = c(0, 1, 5, 15)
)
#> $matrix
#>          contact.age.group
#> age.group      [0,1)     [1,5)   [5,15)      15+
#>    [0,1)  0.40000000 0.8000000 1.266667 5.933333
#>    [1,5)  0.11250000 1.9375000 1.462500 5.450000
#>    [5,15) 0.02450980 0.5049020 7.946078 6.215686
#>    15+    0.03230337 0.3581461 1.290730 9.594101
#> 
#> $participants
#>    age.group participants proportion
#>       <char>        <int>      <num>
#> 1:     [0,1)           15 0.01483680
#> 2:     [1,5)           80 0.07912957
#> 3:    [5,15)          204 0.20178042
#> 4:       15+          712 0.70425321
#>