flexurba 0.2.2

Process CRAN feedback:

Arguments filenames in flexurba::download_GHSLdata(), and output_filenames and global_filenames in flexurba::crop_GHSLdata() are now required as per CRAN policy.
Minor changes to unit test such that files created in the temporary directory are cleaned up.
Changes to examples of download_GHSLdata.

flexurba 0.2.1

Update spatial boundaries in flexurba::units_belgium based on data from the Algemene Directie Statistiek - Statistics Belgium, as these are available under Creative Commons CC BY 4.0 licence. Note that analysis that rely on flexurba::units_belgium might have different results.
Update parameter list in the function flexurba::DoU_get_grid_parameters(). The values UC_smooth_pop and UC_smooth_pop_window were missing from Level 1.
Several minor modifications on the developers side of the package to prepare for a CRAN submission.

flexurba 0.2.0

New apply_threshold() identifies urban areas by applying a threshold on grid cells.
New convert_regions_to_grid() convert regions from a vector layer to gridded format.
New R package flexurbaData with global datasets accompanying the Flexurba R package. The package includes processed population and built-up area derived from the Global Human Settlement Layer, and night-time light grid derived from the Earth Observation Group.
New load_proxies_belgium() loads a sample of the proxy datasets in flexurbaData for the country of Belgium.
Two new vignettes: (1) vignette("vig8-apply-thresholds") discussing different thresholding approaches and (2) vignette("vig9-different-proxies") on different proxy datasets used to construct urban boundaries.

The functions that were specifically design to reconstruct the Degree of Urbanisation delineation have been renamed with the prefix DoU_ to make a more consistent API and allowing for a better tab-completion. The old names remain available for backward compatibility.

New name	Old name
`DoU_preprocess_grid()`	`preprocess_grid()`
`DoU_classify_grid()`	`classify_grid()`
`DoU_classify_grid_urban_centres()`	`classify_grid_urban_centres()`
`DoU_classify_gid_urban_clusters()`	`classify_gid_urban_clusters()`
`DoU_classify_grid_rural()`	`classify_grid_rural()`
`DoU_classify_grid_water()`	`classify_grid_water()`
`DoU_get_grid_parameters()`	`get_grid_parameters()`
`DoU_get_optimal_builtup()`	`get_optimal_builtup()`
`DoU_preprocess_units()`	`preprocess_units()`
`DoU_classify_units()`	`classify_units()`
`DoU_preprocess_units()`	`preprocess_units()`
`DoU_load_grid_data_belgium()`	`load_grid_data_belgium()`
`DoU_plot_grid()`	`plot_grid()`
`DoU_plot_units()`	`plot_units()`

The grid classification rules for semi-dense urban clusters in Level 2 of DEGURBA have been modified in July 2024. To reflect the most up-to-date rules, the default flexurba grid parameters for semi-dense urban clusters in DoU_get_grid_parameters() have also been updated. Specifically:
- the minimum density threshold (SDUC_density_threshold) increased from 300 to 900 inhabitants per km²
- the minimum size threshold (SDUC_size_threshold) decreased from 5000 to 2500 inhabitants
- the contiguity rule (SDUC_contiguity_rule) is modified from the queen (=8) to rook (=4) contiguity
- the buffer size for semi-dense urban clusters SDUC_buffer_size is adjusted to 2 km
Note that these changes will affect the results of DoU_classify_grid() and DoU_classify_grid_urban_clusters() if level1is set to FALSE. The previous classification rules for semi-dense urban clusters can still be applied by specifying them explicit in the function argument parameters.
The unit classification rules for Level 2 of DEGURBA have been modified in July 2024. To reflect the most up-to-date rules, the flexurba function DoU_classify_units() is also updated (see the documentation page for more information). The previous classification rules can still be applied by setting the function argument rules_from_2021 to TRUE.
The function reference is restructured and the README, function documentation pages and vignettes are modified to reflect the updates.