add_locked_in_constraints: Add locked in constraints

In prioritizr/prioritizrutils: Utilities for prioritizr

Description

Add constraints to ensure that they are prioritized in the solution. For example, it may be desirable to lock in planning units that are inside existing protected areas so that the solution fills in the gaps in the existing reserve network.

Usage

add_locked_in_constraints(x, locked_in)

Arguments

x	ConservationProblem-class object.
locked_in	Object that determines which planning units that should be locked in. See details for more information.

Details

The locked in planning units can be specified in several different ways:

integer

vector of indices pertaining to which planning units should be locked in.

character

column name in the attribute table values indicating if planning units should be locked in. This option is only available if the planning units in x are a Spatial-class object. The column in the attribute table should have logical (ie. TRUE or FALSE) values indicating if the planning unit is to be locked in.

Raster-class object

planning units in x that intersect with cells in y are locked in. Specifically, only if the intersect with cells in y are that are not equal to zero or NA.

Spatial-class object.

planning units in x that spatially intersect with locked_in are locked in.

Value

ConservationProblem-class object.

See Also

constraints, penalties.

Examples

# create basic problem
p1 <- problem(sim_pu_polygons, sim_features) %>%
  add_min_set_objective() %>%
  add_relative_targets(0.2)

# create problem with added locked in constraints using integers
p2 <- p1 %>% add_locked_in_constraints(which(sim_pu_polygons$locked_in))

# create problem with added locked in constraints using a field name
p3 <- p1 %>% add_locked_in_constraints("locked_in")

# create problem with added locked in constraints using raster data
p4 <- p1 %>% add_locked_in_constraints(sim_locked_in_raster)

# create problem with added locked in constraints using spatial polygons data
locked_in <- sim_pu_polygons[sim_pu_polygons$locked_in == 1,]
p5 <- p1 %>% add_locked_in_constraints(locked_in)


# solve problems
s1 <- solve(p1)
s2 <- solve(p2)
s3 <- solve(p3)
s4 <- solve(p4)
s5 <- solve(p5)

# plot solutions
par(mfrow=c(3,2))
plot(s1, main="none locked in")
plot(s1[s1$solution==1,], col="darkgreen", add=TRUE)

plot(s2, main="locked in (integer input)")
plot(s2[s2$solution==1,], col="darkgreen", add=TRUE)

plot(s3, main="locked in (character input)")
plot(s3[s3$solution==1,], col="darkgreen", add=TRUE)

plot(s4, main="locked in (raster input)")
plot(s4[s4$solution==1,], col="darkgreen", add=TRUE)

plot(s5, main="locked in (polygon input)")
plot(s5[s5$solution==1,], col="darkgreen", add=TRUE)

prioritizr/prioritizrutils documentation built on May 25, 2019, 12:20 p.m.