Calculate shares for distributing people among subregions

Usage

calculate_shares(data, col, age_group = "default")

data: data frame, historical records (e.g., immigration from other cantons or countries) aggregated across demographic groups.
col: character, name of the column which contains the data for historical occurrences.
age_group: character (optional), either 1-year, 5-year, or 10-year age group used as basis for calculating shares. If the argument is not specified, the default attempts to avoid age groups without any observations. It prioritizes age groups based on their resolution (1-year age groups = most informative and highest priority, 10-year age groups = least informative and lowest priority). Users can override the default and enforce the use of a specific age group for all demographic groups by setting the argument to "age_group_5" or "age_group_10".

Returns the input data frame with the following new columns:

age_group_5: character, indicates the 5-year age group to which the 1-year age group is assigned to.
age_group_10: character, indicates the 10-year age group to which the 1-year age group is assigned to.
sum_5: numeric, total number of people in the 5-year age group.
prop_5: numeric, proportion of the the 5-year age group total that is allocated to each 1-year age group.
sum_10: numeric, total number of people in the 10-year age group.
prop_10: numeric, proportion of the the 10-year age group total that is allocated to each 1-year age group.
use_age_group: character, preference for 1-year, 5-year, or 10-year age group. Defaults to age_group_1 if at least one observation was recorded in all 5 years belonging to the respective 5-year age groups.
n: numeric, number of people to be used according to use_age_group to compute the share.
n_sum: numeric, total per demographic group and across all spatial units.
share: numeric, the spatial unit's share relative to the total of people within the same demographic group (across all spatial units; i.e., n / n_sum).