# accessibility 1.5.0

## New features

- New function `constrained_accessibility()`, which implements the family of 
constrained accessibility measures proposed in \url{https://doi.org/10.1371/journal.pone.0335951}

## Minor changes

- The function `fgt_poverty()` has a new argument `poor_below_threshold`. when
set to `TRUE` (default,) the observations below the poverty line are considered 
to be poor. This is the correct approach for primal accessibility measures (e.g.
cumulative accessibility). If `FALSE`, then observations above the poverty line 
are considered to be poor. This is the correct approach for dual accessibility 
measures (e.g. travel time to the closest facility). When set to `FALSE`, FGT 1 
and 2 do not have an upper bound. Closes [#63](https://github.com/ipeaGIT/accessibility/issues/63)



# accessibility 1.4.0

## Bug fixes

- Fixed a bug in which land use data passed to accessibility functions as a
  `tibble` could lead to an error.

## New features

- New function `decay_logistic()`.

## Notes

- Package description has been adjusted to better reflect the current set of
  available features.

# accessibility 1.3.0

## New features

- New parameter `detailed_results` to `spatial_availability()`, used to specify
  whether results should be aggregated by origin-destination pair or by origin.
  When aggregation by origin-destination pair, the output also includes the
  demand, impedance and combined balancing factors used to calculate spatial
  availability.

# accessibility 1.2.0

## New features

- New inequality functions `concentration_index()` and `theil_t()`.

## Notes

- Various documentation tweaks.
- Testing performance has greatly improved.

# accessibility 1.1.0

## New features

- The package now includes functions to estimate accessibility inequalities
  (`palma_ratio()` and `gini_index()`) and poverty (`fgt_poverty()`).
- New accessibility functions `spatial_availability()` and `balancing_cost()`.
- New vignette "Calculating accessibility inequality and poverty".
- `cost_to_closest()` parameter `n` now accepts a numeric vector, instead of
  being restricted to a single number.
- `cumulative_cutoff()` parameters `cutoff` and `travel_cost` now accepts a
  numeric and a character vector, respectively, instead of being restricted to
  a single number/string.
- `cumulative_interval()` parameter `interval` now accepts a list of numeric
  vectors, instead of being restricted to a single vector.
- The decay functions can now take numeric vectors as input, instead of being
  restricted to a single number (in the case of `decay_stepped()`, both `steps`
  and `weights` can take a `list` of `numeric` vectors as input, instead of
  being restricted to a single `numeric` vector each).

## Notes

- Various documentation tweaks.
- Added the new accessibility functions to the intro vignette.

# accessibility 1.0.1

## Bug fixes

- Fixed a bug in which `cost_to_closest()` would return `NA` values when
  filling missing ids (which should be filled with `Inf`, since they cannot
  reach any opportunities). This was also responsible for the warning reported
  in #27, which was also fixed.

# accessibility 1.0.0

The package has been to tremendous changes. Basically, there's not a single
part of it that remained untouched: documentation, vignettes, function names,
parameter names, extra functionality, performance improvements, etc. While it
is impossible to highlight everything that has been done, we'll try to summary
some of the key points in the following topics.

## Breaking changes

- Accessibility functions previously worked with a single input dataset:
  `data`. Now they require two input datasets: `travel_matrix` and
  `land_use_data`.
- Function names were changed:
  - `time_to_closest()` -> `cost_to_closest()`
  - `cumulative_time_cutoff()` -> `cumulative_cutoff()`
  - `cumulative_time_interval()` -> `cumulative_interval()`
  - `gravity_access()` -> `gravity()`
- Parameter names were changed:
  - `opportunity_col` -> `opportunity`
  - `travel_cost_col` -> `travel_cost`
  - `by_col` -> `active`
  - In `cost_to_closest()`: `n_opportunities` -> `n`
  - In `cumulative_interval()`: `stat` -> `summary_function`
  - In `floating_catchment_area()`: `population_col` -> `demand`
  - In `floating_catchment_area()`: `fca_metric` -> `method`
- Parameter required values were changed:
  - `active` now takes a `logical`, instead of a string (which `by_col`
    previously took).
  - In `cumulative_interval()`: `summary_function` now takes a `function`,
    instead of a string (which `stat` previously took).

## New features

- New function `decay_stepped()`.
- New parameter `interval_increment` to `cumulative_interval()`, used to
  specify how many travel cost units separate the cutoffs used to calculate the
  accessibility estimates which will be used to calculate the summary estimate
  within the specified interval.
- All accessibility functions gained a `group_by` parameter, that allows
  accessibility estimates to be grouped by one or more columns present in
  `travel_matrix`.
- All accessibility functions (but `cumulative_interval()`) gained a
  `fill_missing_ids` parameter, that includes in the results origins whose
  accessibility would be 0 but, due to some commonly overlooked implementation
  details, are usually left out from the output. `cumulative_interval()` doesn't
  have this parameter because its result will always include all origins,
  otherwise the summary measure wouldn't be calculated properly.

# accessibility 0.1.0

- Initial CRAN release.
