spatialsample 0.2.0

New features

• spatial_buffer_vfold_cv() is a new function which wraps
  rsample::vfold_cv(), allowing users to add inclusion radii and exclusion
  buffers to their vfold resamples. This is the supported way to perform
  spatially buffered leave-one-out cross validation (set v to nrow(data)).

• spatial_leave_location_out_cv() is a new function with wraps
  rsample::group_vfold_cv(), allowing users to add inclusion radii and
  exclusion buffers to their vfold resamples.

• spatial_block_cv() is a new function for performing spatial block
  cross-validation. It currently supports randomly assigning blocks to folds.

• spatial_clustering_cv() gains an argument, cluster_function, which
  specifies what type of clustering to perform. cluster_function = "kmeans",
  the default, uses stats::kmeans() for k-means clustering, while
  cluster_function = "hclust" uses stats::hclust() for hierarchical
  clustering. Users can also provide their own clustering function.

• spatial_clustering_cv() now supports sf objects! Coordinates are inferred
  automatically when using sf objects, and anything passed to coords will
  be ignored with a warning. Clusters made using sf objects will take
  coordinate reference systems into account (using sf::st_distance()),
  unlike those made using data frames.

• All resampling functions now support spatial buffering using two arguments.
  radius lets you specify an inclusion radius for your test set, where any
  data within radius of the original assessment set will be added to the
  assessment set. buffer specifies an exclusion buffer around the test set,
  where any data within buffer of the assessment set (after radius is
  applied) will be excluded from both sets.

• autoplot() now has a method for spatial resamples built from sf objects.
  It works both on rset objects and on rsplit objects, and has a special
  method for outputs from spatial_block_cv().

• boston_canopy is a new dataset with data on tree canopy change over time in
  Boston, Massachusetts, USA. It uses a projected coordinate reference system
  and US customary units; see ?boston_canopy for instructions on how to
  install these into your PROJ installation if needed.

Documentation

• The "Getting Started" vignette has been revised to demonstrate the new
  features and clustering methods.

• A new vignette has been added walking through the spatial buffering process.

Dependency changes

• R versions before 3.4 are no longer supported.

• glue, sf, and units have been added to Imports.

• ggplot2 has been moved to Imports. It had been in Suggests.

• covr, gifski, lwgeom, and vdiffr are now in Suggests.

• rlang now has a minimum version of 1.0.0 (was previously unversioned).