forestSAS (version 1.0.1)

pv: Preference value

Description

A descriptive index to analyze the forest saptial structure indices

Usage

pv(index, optm)

Arguments

index

Actual value of forest spatial structure indices

optm

Optimal value of forest spatial structure indices

Value

Result of forest spatial structure heterogeneity assessment

References

None

Examples

# NOT RUN {
data(tree.ppp)
##Get the tree attributies of nearest neighbour 
nnindices<-nnIndex(tree.ppp,N=4,
            smark=c("sp.code","dbh.cm","storey",
               "crownwid.m","group","biomass.kg",
               "quality","x","y"),buffer=FALSE)

#Species mingling
M<-fsasN4(nnindices$nnsp.code,match.fun=mingling)
M
#Stand storey differation degree
H<-fsasN4(nnindices$nnstorey,match.fun=differ)
H
#Tree successional degree
S<-fsasN4(nnindices$nngroup,match.fun=ideal,para="Climax")
S
#Tree quality ideal state
Q<-fsasN4(nnindices$nnquality,match.fun=ideal,
          para=c("Excellent","Good"))
Q
#Tree corwding degree
C<-fsasN4(nnoverlap(nnindices$nncrownwid.m,
         nnindices$nndist),match.fun=crowding)
C
#Tree uniform angle index
W<-fsasN4(nnangle(nnindices$nndist,nnindices$nnx,
           nnindices$nny)$nnangle,
          match.fun=uniform.angle,para=72)
W
#Tree dominance
U<-fsasN4(nnindices$nndbh.cm,match.fun=dominance)
U
#Tree biomass dominance
B<-fsasN4(nnindices$nnbiomass.kg,match.fun=dominance)
B

##Compute the structrue heterogeneity of index
M.pv<-pv(M$result$index,optm=1)
M.pv
H.pv<-pv(H$result$index,optm=1)
H.pv
S.pv<-pv(S$result$index,optm=1)
S.pv
Q.pv<-pv(Q$result$index,optm=1)
Q.pv
C.pv<-pv(C$result$index,optm=0.5)
C.pv
W.pv<-pv(W$result$index,optm=0.5)
W.pv
U.pv<-pv(U$result$index,optm=0)
U.pv
B.pv<-pv(B$result$index,optm=0)
B.pv

##Compute total forest saptial structrue heterogeneity 
#based on the average of indices preference value 
IAVE<-pv(index=c(M$meanI,H$meanI,S$meanI,Q$meanI,
                       C$meanI,W$meanI,U$meanI,B$meanI),
               optm=c(1,1,1,1,0.5,0.5,0,0))
IAVE

##Compute total forest saptial structrue heterogeneity 
#based on the preference value of indices average 
IPVE=mean(M.pv,H.pv,S.pv,Q.pv,C.pv,W.pv,U.pv,B.pv)
IPVE
# }