membership {forestHES}

Standardize the indices by membership functional models

Description

Obtained indices always can not be used to evaluate the forest health because the indices with different dimension. And three membership functional models were thus used to standardize these indices,

Usage

membership(mode = c("up", "down", "mid"), X, L, U, O1, O2)

Arguments

mode

Three membership functional models were thus used to standardize these indices, which are up mode, down mode, and middle mode, respectively. For the up mode, a higher value is better; for the down mode, lower is better; for the middle mode, which have an effective range.

X

The actual observed value of indices

L

Lower limit of the indices

U

Upper limit of the indices

O1

O1 and O2 are the effective range of the indices

O2

O1 and O2 are the effective range of the indices.

Value

Standardized the indices by membership functional models

Author(s)

Zongzheng Chai

References

Zhang HR, and Lei XD. 2014. Health management techniques for typical forest types. Beijing: Publishing house of forestry, China Chai ZZ.2016.National forest health evaluation system at the forest stand level in Chinahttp://www.forest-soil.net/Upload/ueditor/file/20160514/1463221795322480.pdf

Examples

up.index<-membership(mode="up",X=0.67,L=0,U=2.173)
up.index
down.index<-membership(mode="down",X=0.8,L=0,U=2.73)
down.index
mid.index<-membership(mode="mid",X=c(0.1,0.3,0.4,0.6,0.9),L=0.2,U=1.0,O1=0.5,O2=0.7)
mid.index