getHalfTrekSystem {SEMID}

Determines if a half-trek system exists in the mixed graph.

Description

Determines if a half-trek system exists in the mixed graph.

Usage

getHalfTrekSystem(this, fromNodes, toNodes, ...)

## S3 method for class 'MixedGraph'
getHalfTrekSystem(
  this,
  fromNodes,
  toNodes,
  avoidLeftNodes = integer(0),
  avoidRightNodes = integer(0),
  avoidRightEdges = integer(0),
  ...
)

## S3 method for class 'MixedGraph'
getTrekSystem(
  this,
  fromNodes,
  toNodes,
  avoidLeftNodes = integer(0),
  avoidRightNodes = integer(0),
  avoidLeftEdges = integer(0),
  avoidRightEdges = integer(0),
  ...
)

Arguments

this

the mixed graph object

fromNodes

the nodes from which the half-trek system should start. If length(fromNodes) > length(toNodes) will find if there exists any half-trek system from any subset of fromNodes of size length(toNodes) to toNodes.

toNodes

the nodes where the half-trek system should end.

...

ignored.

avoidLeftNodes

a collection of nodes to avoid on the left

avoidRightNodes

a collection of nodes to avoid on the right

avoidRightEdges

a collection of edges between observed noes in the graph that should not be used on any right hand side of any trek in the trek system.

avoidLeftEdges

a collection of edges between observed nodes in the graph that should not be used on any right hand side of any trek in the trek system.

Value

a list with two named components, systemExists (TRUE if a system exists, FALSE otherwise) and activeFrom (the subset of fromNodes from which the maximal half-trek system was started).