An R package to calculate spatial access and availability metrics.
Catchments (catchment areas) are regions defined by the effective range of a catching entity (or the result of its catching). For example, a basin might catch water, a hospital patients, a school students, or a store or restaurant customers. Each of these entities might have any number of conceptual catchments, such as those externally defined (like a school district), those realized (as by the origin of actual customers), and those projected (such as a travel-time radius).
Introduction to Floating Catchment Areas walks through tractable examples.
catchment_ratio is the main function, used to define catchments by a travel-cost matrix with bounds and/or a decay function, and calculate supply to demand ratios within them. It is a generalized implementation of a range of 2- and 3-step floating catchment area models, which is generally meant to align with those of the access Python package.
Installation
Download R from r-project.org, then install the package from an R console:
# install.packages('remotes')
remotes::install_github('uva-bi-sdad/catchment')And load the package:
library(catchment)