A data.frame with the link properties (from, to, cost-distance,
Euclidean distance)
Arguments
proj_name
A character string indicating the Graphab project name.
The project name is also the name of the project directory in which the
file proj_name.xml is.
linkset
A character string indicating the name of the link set
whose properties are imported. The link set has been created with Graphab
or using graphab_link function.
proj_path
(optional) A character string indicating the path to the
directory that contains the project directory. It should be used when the
project directory is not in the current working directory. Default is NULL.
When 'proj_path = NULL', the project directory is equal to getwd().