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Create a fully defined DAG object from a lazy_DAG object

set_lazy_dag.Rd

Given a un-evaluated lazy_DAG object, created using the lazy_dag function and a named list or vector of parameters, this function returns a fully specified DAG object that can then be used to run actual simulations using sim_from_dag, sim_discrete_time or sim_discrete_event. See details and ?lazy_dag for more information.

Usage

set_lazy_dag(lazy_dag, params)

Arguments

lazy_dag

A lazy_DAG object created using the lazy_dag function. See ?lazy_dag for more information on how to specify a lazy DAG. See ?node for more information on how to specify a regular DAG.

params

A named list or a named vector, containing one entry per param() call used in the creation of the lazy_dag object. These entries should be scalar values that can be subsituted directly into the DAG definition.

Details

Given the previously un-evaluated lazy_DAG object, this function substitutes all param() pieces with the corresponding parameter defined in params and then finally evaluates the DAG. Note that the lazy_DAG object itself is not changed in place, so that the set_lazy_dag() function may be used multiple times on the same lazy_DAG to create multiple different data generation processes.

Value

Returns a DAG object.

Author

Robin Denz

Examples

library(simDAG)

# define a lazy DAG with one unspecified parameter
ldag <- lazy_dag(
  empty_dag() +
    node("A", type="rnorm", mean=1, sd=param(SD))
)

# get a real DAG object with SD = 1 and another with SD = 2
dag1 <- set_lazy_dag(ldag, params=c(SD=1))
dag2 <- set_lazy_dag(ldag, params=c(SD=2))

# define some lazy DAG, leaving the intercept of "death" and one beta
# coefficient of "smoking" unspecified
ldag <- lazy_dag(
  empty_dag() +
    node("age", type="rnorm", mean=10, sd=2) +
    node("sex", parents="", type="rbernoulli", p=0.5) +
    node("smoking", type="binomial",
         formula= ~ -2 + age*param(Sbeta) + sex*0.2) +
    node("death", type="binomial",
         formula= ~ param(Dintercept) + age*1 + sex*2)
)

# get a real DAG object from this with set values
dag3 <- set_lazy_dag(ldag, params=c(Sbeta=2.1, Dintercept=-10))