v0.1.0

##New features

• record_group() - strata argument. Perform record grouping separately within subsets of a dataset.
• overlap(), compress_number_line(), fixed_sepisodes(), rolling_episodes() and episode_group() - overlap_methods and methods arguments replaces overlap_method and method respectively. Use different sets of methods within the same dataset when grouping episodes or collapsing number_line objects. overlap_method and method only permits 1 method per per dataset.
• epid objects - win_nm slot. Shows the type of window each event belongs to i.e. case or recurrence window
• epid objects - win_id slot. Unique ID for each window. The ID is the sn of the reference event for each window
  • Format of epid objects updated to reflect this
• epid objects - dist_from_wind slot. Shows the duration of each event from its window's reference event
• epid objects - dist_from_epid slot. Shows the duration of each event from its episode's reference event
• episode_group() and rolling_episodes() - recurrence_from_last argument. Determine if reference events should be the first or last event from the previous window.
• episode_group() and rolling_episodes() - case_for_recurrence argument. Determine if recurrent events should have their own case windows or not.
• episode_group(), fixed_episodes() and rolling_episodes() - data_links argument. Ungroup episodes that do not include records from certain data_source(s).
• episode_group(), fixed_episodes() and rolling_episodes() - case_length and recurrence_length arguments. You can now use a range (number_line object).
• episode_group(), fixed_episodes() and rolling_episodes() - case_length and recurrence_length arguments. You can now use a range (number_line object).
• episode_group(), fixed_episodes() and rolling_episodes() - include_index_period argument. If TRUE, overlaps with the index event or period are groupped together even if they are outside the cut-off range (case_length or recurrence_length).
• pid objects - link_id slot. Shows the record (sn slot) to which every record in the dataset has matched to.
• invert_number_line() - Invert the left and/or right points to the opposite end of the number line
• left_point(x)<-, right_point(x)<-, start_point(x)<- and end_point(x)<- accessor functions

##Changes

• overlap() renamed to overlaps(). overlap() is now a convenience overlap_method for ANY kind of overlap
• "none" is another convenience overlap_method for NO kind of overlap
• expand_number_line() - new options for point; "left" and "right"
• compress_number_line() - compressed number_line object inherits the direction of the widest number_line among overlapping group of number_line objects
• overlap_methods - have been changed such that each pair of number_line objects can only overlap in one way. E.g.
  • "chain" and "aligns_end" used to be possible but this is now considered a "chain" overlap only
  • "aligns_start" and "aligns_end" use to be possible but this is now considered an "exact" overlap
• number_line_sequence() - Output is now a list.
• number_line_sequence() - now works across multiple number_line objects.
• to_df() - can now change number_line objects to data.frames.
  • to_s4() can do the reverse.
• epid objects are the default outputs for fixed_episodes(), rolling_episodes() and episode_group()
• pid objects are the default outputs for record_group()
• In episode grouping, the case_nm for events that were skipped due to rolls_max or episodes_max is now "Skipped".
• In episode_group() and record_group(), sn can be negative numbers but must still be unique
• Optimised episode_group() and record_group(). Runs just a little bit faster ...
• Relaxed the requirement for x and y to have the same lengths in overlap functions.
  • The behaviour of overlap functions will now be the same as that of standard R logical tests
• episode_group - case_length and recurrence_length arguments. Now accepts negative numbers.
  • negative "lengths" will collapse two periods into one, if the second one is within some days before the end_point() of the first period.
    • if the "lengths" are larger than the number_line_width(), both will be collapsed if the second one is within some days (or any other episode_unit) before the start_point() of the first period.
• cheat sheet updated