Positions of origin and destination locations in a spatial interaction model
Source:R/sim_positions.R
location_positions.RdThese functions provide low level access to origin and destination local
positions. It is recommended to use origin_positions() and
destination_positions() instead of location_positions and
location_positions<-.
Value
for location_positions NULL or a list with two components:
origin for the origin location positions and destination for the
destination location positions. For location_positions<-() the modified
sim object.
Positions
Location positions are given by numeric matrices with 2 or 3 columns. The
first two columns are assumed to be geographical coordinates while the 3rd
column can be used for instance to store altitude. Coordinates are interpreted
as is in graphical representations (see autoplot.sim()). They are not matched
to the costs as those can be derived from complex movement models and other
non purely geographic considerations.
Examples
positions <- matrix(rnorm(10 * 2), ncol = 2)
distances <- as.matrix(dist(positions))
production <- rep(1, 10)
attractiveness <- rep(1, 10)
model <- static_blvim(distances, production, 1.5, 1, attractiveness)
## No positions
location_positions(model) <- list(origin = positions, destination = positions)
destination_positions(model)
#> [,1] [,2]
#> [1,] -0.3780286 -1.63463827
#> [2,] 1.7361110 -0.01044112
#> [3,] -0.8452478 -0.65650614
#> [4,] -0.9615715 -0.66953344
#> [5,] 1.0174911 -0.47858903
#> [6,] -1.4960537 1.31945632
#> [7,] -1.1848187 0.63656276
#> [8,] 0.6302344 0.51432778
#> [9,] 2.1012525 -1.75137511
#> [10,] -0.6137368 0.89359752
origin_positions(model)
#> [,1] [,2]
#> [1,] -0.3780286 -1.63463827
#> [2,] 1.7361110 -0.01044112
#> [3,] -0.8452478 -0.65650614
#> [4,] -0.9615715 -0.66953344
#> [5,] 1.0174911 -0.47858903
#> [6,] -1.4960537 1.31945632
#> [7,] -1.1848187 0.63656276
#> [8,] 0.6302344 0.51432778
#> [9,] 2.1012525 -1.75137511
#> [10,] -0.6137368 0.89359752