| plot.thull {labdsv} | R Documentation |
Plotting a Tensioned Hull
Description
A tensioned hull is a minimum volume container for specified elements of an ordination. A ‘thull’ object is returned as an invisible object by plotting a thull of an NMDS or PCO (or MFSO). Subsequently plotting the returned thull results in an ‘image’ of the representation.
Usage
## S3 method for class 'thull'
plot(x,col=rainbow(20),levels=NULL,cont=TRUE,
xlab=x$xlab,ylab=x$ylab,main=x$main,...)
Arguments
x |
an object of class ‘thull’ from function thull |
col |
the color to use plotting the contours |
levels |
the specific levels desired for the contours |
cont |
a logical variable to control plotting contours on the image representation of the tensioned hull |
xlab |
the X axis label |
ylab |
the Y axis label |
main |
the main title |
... |
other graphics parameters |
Details
Tensioned hull analysis fits a minimum volume envelope to specific
points in an ordination. A tensioned hull object is returned from function
thull of a ordination of class ‘dsvord’. This function plots the
resulting tensioned hull as an image, with optional overlays of contours.
Value
Produces a plot on the current graphic device.
Author(s)
David W. Roberts droberts@montana.edu
Examples
data(bryceveg) # returns a data.frame called bryceveg
dis.bc <- dsvdis(bryceveg,'bray') # calculates a Bray-Curtis
# dissimilarity matrix
nmds.bc <- nmds(dis.bc) # calculates an NMDS ordination
plot(nmds.bc) # plots the ordination on the current device
demo.thull <- thull(nmds.bc,bryceveg$arcpat,0.25) # calculates
# the tensioned hull representing the
# distributtion of a species
plot(demo.thull) # portrays the image version of the tensioned hull