rectLookup {SearchTrees}

Perform Rectangular Lookup in 2d Space

Description

Determine which objects, stored in a SearchTrees indexing object, fall within a given rectangle in two-dimensional space.

Usage

rectLookup(tree, ptOne, ptTwo, xlims, ylims)

Arguments

tree

SearchTree. A SearchTree object to perform the lookup on.

ptOne

Numeric. A numeric of length two indicating x and y values for one corner of the rectangle.

ptTwo

Numeric. A numeric of length two indicating x and y values for the corner of the rectangle opposite to ptOne

xlims

Numeric. A numeric vector indicating the minimum and maximum x value for the rectangle. Overrides ptOne and ptTwo

ylims

Numeric. A numeric vector indicating the minimum and maximum y value for the rectangle. Overrides ptOne and ptTwo

Details

In the case of lookup for rectangular objects, any rectangle which overlaps the query rectangle will be returned.

Value

A numeric vector indicating the indicies of the object (in the order they were in when the SearchTree object was created) which fall (at least partially) within the rectangular query.

Author(s)

Gabriel Becker

See Also

QuadTree knnLookup

Examples

x = rnorm(100)
y = rnorm(100)
x2 = x + runif(100, .5, 2)
y2 = y + runif(100, .5, 2)
dat2 = cbind(x, y, x2, y2)
tree2 = createTree(dat2, dataType="rect", columns= 1:4)
inrect = rectLookup(tree2, xlim = c(0,1), ylim=c(0, 1))
col = rgb(0, 1, 0, alpha=.5)
plot(x, y2, col="white")
rect(x[inrect], y[inrect], x2[inrect], y2[inrect], col=col)
rect(0, 0, 1, 1, col="blue", lwd=3)