Changes in version 2.6.4.9000                      

  - New method get_interval_duration() which returns the number of days
    covered by an element of an incidence objects date_index.

                 Changes in version 2.6.4 (2026-03-02)                  

  - Small tweaks to vignette css and js.

                 Changes in version 2.6.3 (2025-06-04)                  

  - Error and warning conditions thrown by incidence2 now have classes
    incidence2_error and incidence2_warning respectively. This was
    announced in the previous release but unfortunately the
    implementation was incomplete. Hopefully the ones that slipped
    through are now classed as described.

                 Changes in version 2.6.2 (2025-04-14)                  

  - Error and warning conditions thrown by incidence2 now have classes
    incidence2_error and incidence2_warning respectively.

  - Where Dates are used for date_index inputs without specification of
    an interval argument, they are checked for 'wholeness' and a warning
    given if any fractional parts are present. Motivated by discussion
    with @avallecam and @joshwlambert over in
    https://github.com/reconhub/incidence/issues/134.

                 Changes in version 2.6.1 (2025-03-11)                  

  - No functional changes, only:
      - documentation consolidation; and
      - we now use litedown for the vignette.

                 Changes in version 2.6.0 (2024-11-22)                  

  - Experimental: When calling incidence() if users specify an
    integer(ish) interval on an (integerish) date input these inputs
    will be coerced in to grates_int_period objects. This fixes
    https://github.com/reconverse/incidence2/issues/121 and (broadly)
    restores earlier behaviour of the incidence() function. This
    functionality is subject to change and, for that reason, is not
    widely documented.
    
    library(incidence2)
    x <- data.frame(onset = c(1, 3, 4, 4, 3, 4, 10))
    
    # 2.5.0 release would error, e.g.
    incidence(x, "onset", interval = 1)
    #> Error in as_period.default(): Not implemented for class [numeric].
    
    # This release - now works
    incidence(x, "onset", interval = 1)
    #> # incidence:  4 x 3
    #> # count vars: onset
    #>   date_index count_variable count
    #>   <intper>   <chr>          <int>
    #> 1 1          onset              1
    #> 2 3          onset              2
    #> 3 4          onset              3
    #> 4 10         onset              1

                 Changes in version 2.5.0 (2024-10-06)                  

  - When the incidence2 class is dropped during an operation we now
    return a tibble instead of a data frame. This is a breaking change
    due to tibble / data frame difference but should have been made as
    part of the 2.3.0 release where the underlying class changed from a
    simple data frame to a tibble. Thanks to @avallecam for the report
    (#120).

                 Changes in version 2.4.0 (2024-09-02)                  

  - incidence() gains a fill parameter. This is passed to
    complete_dates() so is only valid when the argument complete_dates =
    TRUE.

  - For convenience we now reexport select() from dplyr as well as
    unnest() and unpack() from tidyr.

  - Alt text has been added to all vignette images.

  - Improved input checking for keep_first() and keep_last().

                 Changes in version 2.3.1 (2024-05-31)                  

  - Temporarily remove the ympes dependency due to up stream changes.

  - No other user facing changes.

                 Changes in version 2.3.0 (2024-05-23)                  

New functions / features

  - The bootstrap_incidence(), estimate_peak() and first_peak()
    functions, and have been integrated from the downstream i2extras
    package.

  - Added group-aware methods for common generics in base R, dplyr and
    tidyr:
    
      - split.incidence2()
      - mutate.incidence2()
      - summarise.incidence2()
      - nest.incidence2()

  - Added coercion methods for tibble and data.table:
    
      - as_tibble.incidence2()
      - as.data.table.incidence2()

  - New methods, $<-.incidence2 and rbind.incidence2, that drop the
    incidence2 class if the required invariants are broken.

  - New functions incidence_() and regroup_() that work similar to their
    existing namesakes save for additional support for tidy-select
    semantics in some of their arguments.

  - Named vectors can now be used for the groups and counts arguments of
    incidence() to allow renaming prior to aggregation. Previously this
    was only possible with the date_index input.

  - incidence() gains a complete_dates argument defaulting to FALSE. If
    set this is equivalent of a call to incidence() followed by a call
    to complete_dates() with the default arguments. Users wanting more
    flexibility can still call the complete_dates() function with
    different arguments.

Breaking changes

  - All of the aforementioned new methods would previously have
    dispatched on the underlying data.frame method. If you were relying
    on this behaviour then you will now need to add a call to
    as.data.frame() prior to continuing your pipeline.

  - incidence2 objects are now built upon tibbles rather than standard
    data frames. This means where we do not provide methods for
    incidence2 objects, tibble, as opposed to data.frame, methods will
    be called. An overview of the differences between tibbles and
    data.frames can be found at
    https://tibble.tidyverse.org/articles/invariants.html.

  - incidence() now warns if a count variable contains missing values
    and encourages users to handle these prior to calling incidence().

  - The Package now has a hard dependency on the R version (>= 4.1.0).

                 Changes in version 2.2.3 (2023-12-05)                  

Bug fixes

  - plot.incidence2() now works again when applied to incidence2 objects
    with a grates_period date_index. This was inadvertently broken in
    the 2.2.1 release. Thanks to @Bisaloo for the report (#110).

                 Changes in version 2.2.1 (2023-06-13)                  

New features

  - plot.incidence2() gains arguments n_breaks, fill, show_cases and
    legend allowing for a wider range of plot styles. See
    vignette("incidence2", package = "incidence2") for examples.

                 Changes in version 2.1.0 (2023-05-30)                  

New features

  - Specifying interval = "day" or interval = daily in a call to
    incidence will force the resultant date_index variable to be a Date.
    Functionally this is a wrapper around as.Date() that ensures the
    underlying data are whole numbers and that time zones are respected.

(minor) breaking changes

  - incidence() will now warn if objects are created with POSIXct
    columns. The motivation for this is that, internally, POSIXct
    objects are represented as seconds since the UNIX epoch and, in our
    experience, this level of granularity is not normally desired for
    aggregation.

  - The by parameter of complete_dates() is now defunct. This was
    previously passed to an underlying seq function when, in practice,
    it should always have been forced to 1 to match the precision of the
    underlying date_index.

  - complete_dates() will now error if called on an input with a POSIXct
    date_index. Users must now explicitly set the argument allow_POSIXct
    = TRUE to maintain old behaviour.

                 Changes in version 2.0.0 (2023-03-17)                  

Version 2.0.0 is a major, breaking release of incidence2. We have
undertaken a significant refactor that both simplifies the underlying
code base and makes the user interface more consistent and robust.
Although the main changes are highlighted below, users are strongly
advised to read through the accompanying documentation and vignettes.

breaking changes

  - We no longer support NSE (e.g. tidyselect semantics) within the
    package. Our motivation for removing support for NSE are both the
    complexity it can bring to the underlying code (making long term
    maintenance harder) and the complexity it can cause for other users
    / developers who want to build on top of incidence2.

  - new_incidence(), validate_incidence(), build_incidence(), get_n(),
    get_interval(), get_timespan() and facet_plot() are now defunct and
    will error if called.

  - complete_counts() is now renamed complete_dates() and gains two new
    parameters, expand and by. If expand is TRUE (default) then
    complete_dates() will attempt to use function(x) seq(min(x), max(x),
    by = by) to generate a complete sequence of dates.

  - The incidence() function now always returns output in long format
    with dedicated columns for the count variables and values (set by
    arguments count_names_to and count_values_to).

  - incidence() is now less flexible in what it can accept for the
    interval argument. For more complex date groupings users are
    encouraged to perform their require data transformations prior to
    calling incidence().

  - The default plotting of incidence objects as been greatly
    simplified. Sensible defaults have been chosen to enable a quick
    visual overview of incidence objects but users are advised to call
    ggplot2 directly for more bespoke plotting.

                 Changes in version 1.2.3 (2021-11-07)                  

New functions

  - Reintroduces the cumulate() functionality (previously deprecated
    in 1.2.0).

Breaking changes

  - Default fill argument in complete_counts() is now 0 rather than NA.

                 Changes in version 1.2.2 (2021-08-23)                  

Bug fixes

  - Fixes bug when input object to incidence is a data.table.

                 Changes in version 1.2.1 (2021-07-14)                  

Bug fixes

  - Fixes bug in incidence() when more than one column was given for the
    date_index.
  - Fixes incorrect test that did not take in to account changing time
    zones.

                 Changes in version 1.2.0 (2021-07-07)                  

New functions

  - new_incidence(): A minimal incidence constructor.
  - validate_incidence(): Check for internal consistency of
    incidence-like object.
  - build_incidence(): Allows you to construct an incidence object
    whilst specifying your own date grouping function.
  - format.incidence()

Deprecated functions

  - cumulate() will now give a deprecation error. We have removed the
    function to avoid users erroneously regressing against a cumulative
    count.

Bug fixes

  - Fixes bug in incidence() when dates were a character vector and the
    the default, daily, interval was specified.

Other updates

  - Now uses dplyr to handle list based columns (e.g. record-type
    objects from vctrs). For data.frames with only atomic columns,
    data.table is still used.
  - Printing and summaries of incidence objects have been improved to
    remove duplication in the overview section.

                        Changes in version 1.1.0                        

  - New function complete_counts().
  - plot() and facet_plot() now have a centre_dates argument which can
    be set to FALSE to get histogram-esque date labels for single month,
    quarter and yearweek groupings.
  - Internal refactoring due to breakages changes in the upstream grates
    package.

                 Changes in version 1.0.0 (2021-03-30)                  

Due to multiple changes in the underlying representation of incidence2
objects this release may possibly break old workflows particularly those
relying on the old implementations of date grouping:

  - Now uses the package grates for date grouping. This introduces the
    s3 classes yrwk, yrmon, yrqtr, yr, period and int_period as well as
    associated constructors which incidence now builds upon. As a result
    of this the aweek dependency has been dropped.
  - Add's keep_first and keep_last functions.
  - Construction of incidence objects now faster due to underlying use
    of data.table.

                 Changes in version 0.2.2 (2020-11-12)                  

  - Fixes bug in get_interval.
  - Removes message that was displayed when incidence class dropped.
  - Refactoring of internal code to improve maintainability.
  - Tests now use the 3rd edition of testthat.

                 Changes in version 0.2.1 (2020-10-16)                  

  - Fixes bug in as.data.frame.incidence2
  - Limits internal reliance on dplyr.

                 Changes in version 0.2.0 (2020-09-22)                  

  - Fixes issue with monthly incidence objects when show_cases = TRUE
    (see #42).
  - Additional checks added for assessing whether a manipulated
    incidence object maintains its class.
  - Improved implementation speed.
  - NA's now ignored in the count variable of a pre-aggregated input to
    incidence function.
  - Fixes axis labelling and spacing.

                 Changes in version 0.1.0 (2020-09-07)                  

  - Initial release.