ecodist (version 2.1.3)

plot.mgram: Plot a Mantel correlogram

Description

Plot a Mantel correlogram from an object of S3 class mgram, using solid symbols for significant values.

Usage

# S3 method for mgram
plot(x, pval = 0.05, xlab = "Distance", ylab = NULL, ...)

Value

draws a plot (graphics device must be active).

Arguments

x

an object of class mgram

pval

cut-off level for statistical significance.

xlab

x-axis label.

ylab

y-axis label.

...

optional, any additional graphics parameters.

Author

Sarah Goslee

See Also

mgram

Examples

# generate a simple surface
x <- matrix(1:10, nrow=10, ncol=10, byrow=FALSE)
y <- matrix(1:10, nrow=10, ncol=10, byrow=TRUE)
z <- x + 3*y
image(z)

# analyze the pattern of z across space
space <- cbind(as.vector(x), as.vector(y))
z <- as.vector(z)
space.d <- distance(space, "eucl")
z.d <- distance(z, "eucl")
z.mgram <- mgram(z.d, space.d, nperm=0)
plot(z.mgram)

#

data(graze)
space.d <- dist(graze$sitelocation)
forest.d <- dist(graze$forestpct)

grasses <- graze[, colnames(graze) %in% c("DAGL", "LOAR10", "LOPE", "POPR")]
legumes <- graze[, colnames(graze) %in% c("LOCO6", "TRPR2", "TRRE3")]

grasses.bc <- bcdist(grasses)
legumes.bc <- bcdist(legumes)

# Does the relationship of composition with distance vary for
# grasses and legumes?
par(mfrow=c(2, 1))
plot(mgram(grasses.bc, space.d, nclass=8))
plot(mgram(legumes.bc, space.d, nclass=8))