dag.init: Set up a new DAG.

Description

Allows setting up a new DAG. See the demo.dag0 to demo.dag6 functions for some example specifications.

Usage

dag.init(outcome = NULL, exposure = NULL, covs = c(), arcs = c(),
 assocs = c(), xgap = 0.04, ygap = 0.05, len = 0.1, y.name = NULL,
 x.name = NULL, cov.names = c(), ...)

Arguments

outcome

Currently not used!

exposure

Currently not used!

covs

Vector including an integer for each covariable to be in the DAG (1 for a "standard" covariable, 2 for an unknown/unmeasured one).

arcs

Vector of duplets of integers, in which nodes from which an arc or undirected association is to emenate are followed by those to which it is to point. To refer to the exposure, use 0, to refer to the outcome, use -1, to refer to covariables, use and eleme

assocs

A vector of same length as covs, with 0 indicating directed arcs, 1 indicating undirected associations.

xgap

How much x space is to be left between arc ends and nodes when drawing?

ygap

How much y space is to be left between arc ends and nodes when drawing?

len

Length of arrow whiskers when drawing.

y.name

Label of outcome.

x.name

Label of exposure.

cov.names

Vector of covariable labels.

...

Currently not used.

Value

A DAG (objects of class dagRdag). Check out some of the demonstration DAGs for details. The DAG is actually a list object, with elements cov.types (the covs vector, with 0 put in front, and -1 at the end).; x and y (coordinates for drawing the nodes, initially set up more or less in a half-circle above the x->y arc); arc (the arcs, transformed into a matrix); arc.type (the assocs vector); curve.x and curve.y (if associations are featured, these provide the coordinates through which to curve); xgap, ygap, len (the respective drawing parameters); version (dagR version).

References

Breitling LP (2010). dagR: a suite of R functions for directed acyclic graphs. Epidemiology 21(4):586-587. Greenland S, Pearl J, Robins JM (1999). Causal diagrams for epidemiologic research. Epidemiology 10(1):37-48.

Examples

Run this code

demo.dag1;
demo.dag1();
demo.dag2;
demo.dag2();