SearchTrees (version 0.1.6)

createIndex: Create a Search Tree Index

Description

Create a search tree from the supplied data for use in during futurelookups.

Usage

createIndex(data, type = "quad", columns = c(1, 2), ...)

Arguments

data

Data to create the tree from. Must be a matrix or data.frame like object.

type

Type of tree structure to create. Currently only "quad" is supported

columns

Which columns in data to use to create the tree. Defaults to columns 1 and 2.

...

Any additional/type specific parameters to be passed to the tree creation function.

Value

• The class of the returned object depends on the tree type created, though all will inherit from the SearchTree S4 class and have the following slots:
• ref
  An external pointer to the C level data structure.
• numNodes
  Total number of nodes comprising the tree.
• dataNodes
  Number of terminal/leaf nodes which store at least one data point.
• maxBucket
  Maximum number of data points stored in a single terminal/leaf node.
• points
  Number of points used to create the tree.

References

Finkel, R. A. and Bentley, J. L. "Quad Trees, a Data Structure for Retrieval on Composite Keys." Acta Informatica 4, 1-9, 1974.

See Also

findKNN, getPointsInRect

Examples

x = rnorm(100)
 y = rnorm(100)
 dat = cbind(x,y)
 #maxDepth is a parameter settable for quad trees
 tree = createIndex(dat, maxDepth = 10, type="quad")