Convert between different distance units - all functions take the form xx2yy where xx is the unit to be converted from and yy is the unit to be converted to.
vulgaris
(Package: GISTools) :
Phenology data for North American lilacs
Data set from Schwartz, M.D. and J.M. Caprio, 2003, North American First Leaf and First Bloom Lilac Phenology Data, IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2003-078. NOAA/NGDC Paleoclimatology Program, Boulder CO, USA.
Takes an ‘mask’ type polygon object - basically a rectangle with a polygon hole cut through it - and draws this over an image. This has the effect of only showing the image inside the hole. This is useful for plotting surfaces defined over a study area, but masking the values outside of the area.
phenology
(Package: GISTools) :
Phenology data for North American lilacs
Data set from Schwartz, M.D. and J.M. Caprio, 2003, North American First Leaf and First Bloom Lilac Phenology Data, IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2003-078. NOAA/NGDC Paleoclimatology Program, Boulder CO, USA.
Operations for bootstrapping and kernel bootstrapping based on point data. bstrap.points sample n points with replacement from a sample - and jitter.points adds a Gaussian displacement to each point in a data set. Applying a jitter to a bootstrap effectively creates a kernel bootstrap operation.
providing 
.