ancestors: Get ancestors values
In VEZY/XploRer: Read, Write, Plot and Analyze MTG (Mutli-Scale Tree Graph) Files

Description Usage Arguments Details Value Examples

Get attribute values from all ancestors (basipetal).

ancestors(
  attribute,
  node = NULL,
  scale = NULL,
  symbol = NULL,
  link = NULL,
  filter_fun = NULL,
  self = FALSE,
  continue = TRUE,
  recursivity_level = NULL
)

`attribute`	Any node attribute (as a character)
`node`	The MTG node
`scale`	Integer vector for filtering ancestors by their `.scale` (i.e. the SCALE from the MTG classes).
`symbol`	A character vector for filtering the ancestors by their `.symbol` (i.e. the SYMBOL column from the MTG classes).
`link`	A character vector for filtering the `.link` with the parent (e.g. not a branch)
`filter_fun`	Any filtering function taking a node as input, e.g. `data.tree::isLeaf()`
`self`	Return the value of the current node (`TRUE`), or the ancestors only (`FALSE`, the default)
`continue`	Boolean. If `TRUE`, the function returns all nodes that are not filtered. If `FALSE`, stop at the first node that is filtered out.
`recursivity_level`	The maximum number of recursions allowed (considering filters). E.g. to get the parent only: `recursivity_level = 1`, for parent + grand-parent: `recursivity_level = 2`. If `NULL` (the default), the function returns all values from the node to the root.

This function is mainly intended to be used with mutate_mtg(). In this case, the node argument can be left empty (or node = node equivalently).

The attribute values from the ancestors of the node (from first parent to farther ancestor)

filepath= system.file("extdata", "simple_plant.mtg", package = "XploRer")
MTG = read_mtg(filepath)

# node_6 has four ancestors:
ancestors("Length", node = extract_node(MTG, "node_6"))
# Two of them have no values for Length

# If the value of node_6 is also needed:
ancestors("Length", node = extract_node(MTG, "node_6"), self = TRUE)

# If we only need the value of the first parent:
ancestors("Length", node = extract_node(MTG, "node_6"), recursivity_level = 1)

# We can filter by symbol if we need to return the values for some symbols only:
ancestors("Width", node = extract_node(MTG, "node_6"), symbol = "Internode")

# The values are only returned for the ancestors with the required symbol
# For example we know that a leaf cannot be an ancestor because it cannot bear anything:
ancestors("Width", node = extract_node(MTG, "node_6"), symbol = "Leaf")
# In this case it returns a length 0 vector.