pv: Preference value

In Zongzheng/forestSAS: Forest spatial structure analysis systems

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

Author(s)

Zongzheng Chai, [e-mail]

References

None

Examples

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

Zongzheng/forestSAS documentation built on July 13, 2024, 8:12 p.m.