Dominant Flows Selection
Dominant flows selection.
domflows(mat, w, k)
- A square matrix of flows.
- A vector of units weigths (sum of incoming flows, sum of outgoing flows...).
- A threshold (see 'Details').
This function selects which flow (fij or fji) must be kept. If the ratio weight of destination (wj) / weight of origin (wi) is greater than k, then fij is selected and fji is not. This function can perform the second criterion of the Nystuen & Dacey's dominants flows analysis. As the output is a boolean matrix, use element-wise multiplication to get flows intensity.
A boolean matrix of selected flows.
J. Nystuen & M. Dacey, 1961, "A Graph Theory Interpretation of Nodal Regions.", Papers and Proceedings of the Regional Science Association, 7:29-42.bt
# Import data data(nav) myflows <- prepflows(mat = nav, i = "i", j = "j", fij = "fij") # Remove the matrix diagonal diag(myflows) <- 0 # Select the dominant flows (incoming flows criterion) flowSel <- domflows(mat = myflows, w = colSums(myflows), k = 1) statmat(mat = myflows * flowSel, output = "none")