spp {ads}  R Documentation 
Function spp
creates an object of class "spp"
, which represents a
spatial point pattern observed in a finite sampling window (or study region).
The ads
library supports univariate, multivariate and marked point patterns
observed in simple (rectangular or circular) or complex sampling windows.
spp(x, y=NULL, window, triangles, marks, int2fac=TRUE) ppp2spp(p)
x,y 
if 
window 
a 
triangles 
(optional) a list of triangles removed from a simple initial window to define a
complex sampling window (see 
marks 
(optional) a vector of mark values, which may be factor levels or numerical values (see Details). 
int2fac 
if TRUE, integer marks are automatically coerced into factor levels. 
p 
a 
A spatial point pattern is assumed to have been observed within a specific
sampling window (a finite study region) defined by the window
argument. If window
is a simple "swin"
object,
it may be coerced into a complex type by adding a triangles
argument (see swin
). A spatial point pattern may be of 3 different types.
univariate pattern:
by default when argument marks
is not given.
multivariate pattern:
marks
is a factor, which levels are interpreted as categorical marks (e.g. colours, species, etc.) attached to points of the pattern.
Integer marks may be automatically coerced into factor levels when argument int2fac = TRUE
.
marked pattern:
marks
is a vector of real numbers attached to points of the pattern. Integer values may also be considered as numerical values
if argument int2fac = FALSE
.
An object of class "spp"
describing a spatial point pattern observed in a given sampling window.

a character string indicating if the spatial point pattern is 

an 

an integer value giving the number of points of the pattern located inside the sampling window (points on the boundary are considered to be inside). 

a vector of x coordinates of points located inside the sampling window. 

a vector of y coordinates of points located inside the sampling window. 

(optional) an integer value giving the number of points of the pattern located outside the sampling window. 

(optional) a vector of x coordinates of points located outside the sampling window. 

(optional) a vector of y coordinates of points located outside the sampling window. 

(optional) a vector of the marks attached to points located inside the sampling window. 

(optional) a vector of the marks attached to points located outside the sampling window. 
There are printing, summary and plotting methods for "spp"
objects.
Function ppp2spp
converts an ppp.object
from package spatstat.geom
into an "spp"
object.
Goreaud, F. and P?Pelissier, R. 1999. On explicit formula of edge effect correction for Ripley's Kfunction. Journal of Vegetation Science, 10:433438.
data(BPoirier) BP < BPoirier ## Not run: univariate pattern in a rectangle of size [0,110] x [0,90] swr < spp(BP$trees, win=BP$rect) ## Not run: an alternative using atomic vectors of point coordinates swr < spp(BP$trees, win=BP$rect) summary(swr) plot(swr) ## Not run: univariate pattern in a circle with radius 50 centred on (55,45) swc < spp(BP$trees, win=c(55,45,50)) summary(swc) plot(swc) plot(swc, out=TRUE) # plot points outside the circle ## Not run: multivariate pattern in a rectangle of size [0,110] x [0,90] swrm < spp(BP$trees, win=BP$rect, marks=BP$species) summary(swrm) plot(swrm) plot(swrm, chars=c("b","h","o")) # replace symbols by letters ## Not run: marked pattern in a rectangle of size [0,110] x [0,90] swrn < spp(BP$trees, win=BP$rect, marks=BP$dbh) summary(swrn) plot(swrn) ## Not run: multivariate pattern in a complex sampling window swrt < spp(BP$trees, win=BP$rect, tri=BP$tri1, marks=BP$species) summary(swrt) plot(swrt) plot(swrt, out=TRUE) # plot points outside the sampling window ## Not run: converting a ppp object from spatstat.geom data(demopat) demo.spp<ppp2spp(demopat) plot(demo.spp)