An S4 class to represent sub-annual time resolution structure.

Sub-annual time resolution is represented by nested, named time-frames and time-slices.

Slots

name: character. Name of the calendar object. Use to distingush between different structures and subsets of time-slices. The name is used to propose default folder names for the model/scenario scripts to separate solutions of the same scenario with different calendar objects.
desc: character. Description of the calendar object, for own references.
timeframes: list. Named list of nested sub-annual levels with vectors of individual elements. The top level of the list is the highest level of the calendar, e.g., "ANNUAL". The lowest level is the smallest time-slice, e.g., "MONTH". "ANNUAL" is the default (hardwired) top level of the calendar. All other levels are optional, and create nested sub-annual levels of time-slices. The minimum number of time-slices in a timeframe is two (except for the top level).
year_fraction: numeric. The fraction of a year covered by the calendar, e.g. 1 for annual calendar (default), 0.5 for semi-annual, 0.25 for quarterly, etc. Currently must be specified manually for subset calendars to validate the sum of the shares.
timetable: data.frame. Data frame with levels of timeframes in the named columns, and number of rows equal to the total number of time-slices on the lowest level. Every timeframe is a set of time-slices ("slices") - a named fragment of time with a year-share. Timeframes have nested structure where every slice serves as a parent for the lower level of time-slices (children). The first column is the name of the time-slice, the rest of the columns are the names of the timeframes. The values are the share of the year covered by the time-slice. The sum of the shares in every timeframe should be equal to 1. weight is an optional column with the weight of the time-slice in the year, used for sumpled/subset selection of the time-slices.
slice_share: data.frame. Auto-calculated from the timetable two column data.frame with slices from all levels with their individual share in a year. The first column is the name of the time-slice, the second column is the share of the year covered by the time-slice.
default_timeframe: character. The name of the default level of the time-slices used in the model. If not specified, the lowest level of the timeframes is used as the default timeframe.
timeframe_rank: character. Auto-calculated from the timetable and timeframes slots named character vector with ranks of the timeframes. The rank is used to determine the order of the timeframes in the calendar.
slices_in_frame: integer. Auto-calculated from the timetable Number of time-slices in every timeframe.
slice_family: data.frame. Auto-calculated from the timetable data.frame mapping "parent" to "child" slices in two nearest timeframes in the nested hierarchy. The first column is the name of the parent time-slice, the second column is the name of the child time-slice.
slice_ancestry: data.frame. Auto-calculated from the timetable data.frame mapping "child", "grandchild", etc. slices to the "parent" and "grandparent" time-slices in the full hierarchy. The first column is the name of the (grand-) child time-slice, the second column is the name of the (grand-) parent time-slice.
next_in_timeframe: data.frame. Auto-calculated from the timetable data.frame mapping chronological sequence between time-slices in the same timeframe. The first column is the name of the time-slice, the second column is the name of the next time-slice in the same timeframe.
next_in_year: data.frame. Auto-calculated from the timetable data.frame mapping chronological sequence between time-slices in the same timeframe through the whole year. The first column is the name of the time-slice, the second column is the name of the next time-slice in the same timeframe.
misc: list. Any additional data or information to store in the object.