Builds a sparse adjacency matrix from a user specified
SSN
data directory, by extracting and processing the
binaryID.db
table. The resulting output of this function is
required input for fitting spatial additive network models to SSN
objects using the main smnet
function.
get_adjacency(ssn_directory, netID = 1)
Required character string indicating the path to the location of the .ssn directory which contains the binaryID.db table.
Logical. Integer specifying the particular stream network
of interest within the SSN
object. Defaults to 1.
List object with components
adjacency
: Sparse adjacency matrix of class spam
with row and
column dimension equal to the number of stream segments. If the i^th column
has non-zero elements \(j_1\) and \(j_2\) then this indicates
that \(j_1\) and \(j_2\) are direct upstream neighbours of i.
If the \(i^\textrm{th}\) column has sum 1, then this indicates that
\(i\) has only one upstream neighbour, and therefore no confluence lies
between them; by default the spatial penalties treat these differently.
bid
: Character vector of binary identifiers for each stream segment,
used only for automatic calculation of Shreve's stream order within
smnet