data.tree (version 1.1.0)

GetAttribute: Get an attribute from a Node.

Description

Get an attribute from a Node.

Usage

GetAttribute(
  node,
  attribute,
  ...,
  format = FALSE,
  inheritFromAncestors = FALSE,
  nullAsNa = TRUE
)

Arguments

node

The Node from which the attribute should be fetched.

attribute

determines what is collected. The attribute can be

• a.) the name of a field or a property/active of each Node in the tree, e.g. acme$Get("p") or acme$Get("position")

• b.) the name of a method of each Node in the tree, e.g. acme$Get("levelZeroBased"), where e.g. acme$levelZeroBased <- function() acme$level - 1

• c.) a function, whose first argument must be a Node e.g. acme$Get(function(node) node$cost * node$p)

...

in case the attribute is a function or a method, the ellipsis is passed to it as additional arguments.

format

if FALSE (the default), no formatting is being used. If TRUE, then the first formatter (if any) found along the ancestor path is being used for formatting (see SetFormat). If format is a function, then the collected value is passed to that function, and the result is returned.

inheritFromAncestors

if TRUE, then the path above a Node is searched to get the attribute in case it is NULL.

nullAsNa

If TRUE (the default), then NULL is returned as NA. Otherwise it is returned as NULL.

Examples

data(acme)
GetAttribute(acme$IT$Outsource, "cost")