policy_def {polle}

Define Policy

Description

policy_def returns a function of class policy. The function input is a policy_data object and it returns a data.table with keys id and stage and action variable d.

Usage

policy_def(policy_functions, full_history = FALSE, reuse = FALSE, name = NULL)

Arguments

policy_functions

A single function/character string or a list of functions/character strings. The list must have the same length as the number of stages.

full_history

If TRUE, the full history at each stage is used as input to the policy functions.

reuse

If TRUE, the policy function is reused at every stage.

name

Character string.

Value

Function of class "policy". The function takes a policy_data object as input and returns a data.table with keys id and stage and action variable d.

See Also

get_history_names(), get_history().

Examples

library("polle")
### Single stage"
d1 <- sim_single_stage(5e2, seed=1)
pd1 <- policy_data(d1, action="A", covariates=list("Z", "B", "L"), utility="U")
pd1

# defining a static policy (A=1):
p1_static <- policy_def(1)

# applying the policy:
p1_static(pd1)

# defining a dynamic policy:
p1_dynamic <- policy_def(
  function(Z, L) ((3*Z + 1*L -2.5)>0)*1
)
p1_dynamic(pd1)

### Two stages:
d2 <- sim_two_stage(5e2, seed = 1)
pd2 <- policy_data(d2,
                  action = c("A_1", "A_2"),
                  covariates = list(L = c("L_1", "L_2"),
                                    C = c("C_1", "C_2")),
                  utility = c("U_1", "U_2", "U_3"))

# defining a static policy (A=0):
p2_static <- policy_def(0,
                        reuse = TRUE)
p2_static(pd2)

# defining a reused dynamic policy:
p2_dynamic_reuse <- policy_def(
  function(L) (L > 0)*1,
  reuse = TRUE
)
p2_dynamic_reuse(pd2)

# defining a dynamic policy for each stage based on the full history:
# available variable names at each stage:
get_history_names(pd2, stage = 1)
get_history_names(pd2, stage = 2)

p2_dynamic <- policy_def(
  policy_functions = list(
    function(L_1) (L_1 > 0)*1,
    function(L_1, L_2) (L_1 + L_2 > 0)*1
  ),
  full_history = TRUE
)
p2_dynamic(pd2)