select.randquad {CTFS}R Documentation

Randomly Select the Coordinates of Quadrate

Description

Takes a vector of quadrate sizes and randomly selects a point on the plot as the initial corner. This function is called by spp.randarea.range and is not usually called alone.

Usage

select.randquad(quadside, shape = 1, plotdim = c(1000, 500), replicates = 
100)

Arguments

quadside vector of dimensions (x) of the randomly selected area in meters
shape single value numeric, factor used to determine dimension y of quadrate. for a square, shape = 1
plotdim plot dimensions, x,y lengths in meters
replicates number of randomly selected areas to sample

Details

The dimensions of the selected quadrate are determined by the values in quadside and shape. The quadrate dimensions are x = quadside[i] and y = quadside[i]* shape[i]. If one shape value is provided then it is used for all quadrates. The returned x and y coordinates, paired, define the four corners of the quadrates.

Value

xlo x coordinate
ylo y coordinate
xhi x coordinate
yhi y coordinate
area area of each quadrate in hectares

Author(s)

Rick Condit, Suzanne Lao and Pamela Hall

See Also

CTFS.diversity

Examples

## Not run: 
1. There are no defaults for this function, parameters must be
supplied. This results in 10 sets of coordinates for 1 hectare, square
quadrates.

select.randquad(quadside=100,shape=1,replicates=10)

2. Try a rectangular quadrate and quadrates of different shapes

select.randquad(quadside=100,shape=2,replicates=10)
select.randquad(quadside=100,shape=c(2,3),replicates=10)
select.randquad(quadside=c(10,100),shape=1,replicates=10)
select.randquad(quadside=c(10,100),shape=c(2,3),replicates=10)
## End(Not run)

[Package CTFS version 1.00 Index]