Skip to contents

HypercubeQueue: Larson (1974) hypercube queueing model (zero or infinite line) with unit workloads, dispatch fractions, loss or waiting probability and travel times. SquareRootLaw: Kolesar-Blum response distance. ShortCrimeLattice: Short et al. (2008) agent burglary model on a periodic lattice. ShortCrimePde: its continuum reaction-diffusion version with hotspot suppression. Units and atoms are 0-based in preferences, as in the Python arm morie.fn.policeops.

Usage

HypercubeQueue(
  arrival_rates,
  preferences,
  service_rate = 1,
  queue = "zero",
  travel_time = NULL
)

SquareRootLaw(area, available_units, metric = "euclidean", speed = NULL)

ShortCrimeLattice(
  n,
  steps,
  A0 = 1/30,
  eta = 0.03,
  omega = 1/15,
  gamma = 0.002,
  B0 = NULL,
  criminals = NULL,
  seed = 1
)

ShortCrimePde(
  B,
  rho,
  dx = 1,
  dt = 0.01,
  steps = 100,
  eta = 0.03,
  omega = 1/15,
  A0 = 1/30,
  gamma = 0.002,
  D = 1,
  eps = 1,
  z = 4,
  suppress = NULL
)

Arguments

arrival_rates

Call rates by atom.

preferences

List of unit dispatch orders (0-based) per atom.

service_rate

Service rate per unit.

queue

"zero" or "infinite".

travel_time

Units x atoms travel times.

area, available_units

Area and available units.

metric

"euclidean" or "rectilinear".

speed

Travel speed.

n

Lattice side.

steps

Time steps.

A0, eta, omega, gamma

Model parameters.

B0

Initial dynamic attractiveness (length n^2).

criminals

Initial criminal sites (0-based).

seed

Philox seed.

B, rho

Initial fields (matrices).

dx, dt

Grid spacing and time step.

D, eps, z

Continuum constants.

suppress

0/1 matrix of policed cells.

Value

List.

References

Larson, R. C. (1974). A hypercube queuing model for facility location and redistricting in urban emergency services. Computers and Operations Research 1, 67-95.

Kolesar, P. and Blum, E. H. (1973). Square root laws for fire engine response distances. Management Science 19, 1368-1378.

Short, M. B. et al. (2008). A statistical model of criminal behavior. Mathematical Models and Methods in Applied Sciences 18, 1249-1267.

Examples

HypercubeQueue(1, list(c(0, 1)))$loss
#> [1] 0.2
SquareRootLaw(100, 4)$distance
#> [1] 2.5