Blossom (version 1.3)

fraserf: Subalpine forest tree cover data

Description

Lodgepole pine and Engelmann spruce canopy cover modeled as a function of basal area and density of the trees with least absolute deviation regression.

Usage

data(fraserf)

docType

data

source

Cade, B.S. 1997. Comparison of tree basal area and canopy cover in habitat models: Subalpine forest. Journal of Wildlife Management 61, 326--335.

Examples

panel.cor <- function(x, y, digits = 2, prefix = "", cex.cor, ...)
{
    usr <- par("usr"); on.exit(par(usr))
    par(usr = c(0, 1, 0, 1))
    r <- abs(cor(x, y,method = "spearman"))
    txt <- format(c(r, 0.123456789), digits = digits)[1]
    txt <- paste(prefix, txt, sep = "")
    if(missing(cex.cor)) cex.cor <- 0.8/strwidth(txt)
    text(0.5, 0.5, txt, cex = cex.cor * r)
}

pairs(fraserf[,c(1,2,4,5,6,7)],main = "Lodgepole pine data
 with Spearman correlation coefficient",
     lower.panel = panel.smooth, upper.panel = panel.cor)