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Last data update: 2014.03.03

R: Perform Rectangular Lookup in 2d Space

rectLookup

R Documentation

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

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)

Results


R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> library(SearchTrees)
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/SearchTrees/rectLookup.Rd_%03d_medium.png", width=480, height=480)
> ### Name: rectLookup
> ### Title: Perform Rectangular Lookup in 2d Space
> ### Aliases: rectLookup 'rectLookup, QuadTree-method'
> ### Keywords: rectangular lookup query
> 
> ### ** 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)
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>