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)

Format

A data frame with 31 observations on the following 11 variables.

apico

Basal area (m^2/ha) of lodgepole pine adjusted for slope of terrain.

apien

Basal area (m^2/ha) of Engelmann spruce.

apien2

Basal area squared of Engelmann spruce.

lcc

Lodgepole pine canopy cover.

scc

Englemann spruce canopy cover.

picopha

Lodgepole pine stem density (number/ha).

pienpha

Englemann spruce stem density (number/ha).

z81

The transformation lcc-.81(apico).

z105

The transformation lcc-1.05(apico).

z50

The transformation lcc-.50(apico).

z90

The transformation lcc-.90(apico).

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\n with Spearman correlation coefficient",
     lower.panel = panel.smooth, upper.panel = panel.cor)

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(Blossom)
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/Blossom/fraserf.Rd_%03d_medium.png", width=480, height=480)
> ### Name: fraserf
> ### Title: Subalpine forest tree cover data
> ### Aliases: fraserf
> ### Keywords: datasets
> 
> ### ** 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\n with Spearman correlation coefficient",
+      lower.panel = panel.smooth, upper.panel = panel.cor)
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>