alakazam (version 1.3.0)

getMRCA: Retrieve the first non-root node of a lineage tree

Description

getMRCA returns the set of lineage tree nodes with the minimum weighted or unweighted path length from the root (germline) of the lineage tree, allowing for exclusion of specific groups of nodes.

Usage

getMRCA(
  graph,
  path = c("distance", "steps"),
  root = "Germline",
  field = NULL,
  exclude = NULL
)

Value

A data.frame of the MRCA node(s) containing the columns:

• name: node name

• steps: path length as the number of nodes traversed

• distance: path length as the sum of edge weights

Along with additional columns corresponding to the annotations of the input graph.

Arguments

graph

igraph object containing an annotated lineage tree.

path

string defining whether to use unweighted (steps) or weighted (distance) measures for determining the founder node set..

root

name of the root (germline) node.

field

annotation field to use for both unweighted path length exclusion and consideration as an MRCA node. If NULL do not exclude any nodes.

exclude

vector of annotation values in field to exclude from the potential MRCA set. If NULL do not exclude any nodes. Has no effect if field=NULL.

See Also

Path lengths are determined with getPathLengths.

Examples

# Define example graph
graph <- ExampleTrees[[23]]

# Use unweighted path length and do not exclude any nodes
getMRCA(graph, path="steps", root="Germline")

# Exclude nodes without an isotype annotation and use weighted path length
getMRCA(graph, path="distance", root="Germline", field="c_call", exclude=NA)