Trees {SAFD}

Tree dataset

Description

Trees is a list containing three sublists, each of which consists of a sample of trapezoidal fuzzy numbers. The data corresponds to the quality of the three main species of trees in Asturias, namely birch (Betula celtiberica), sessile oak (Quercus petraea) and rowan (Sorbus aucuparia) within a study about the progress of reforestation in a given area of Asturias (Spain). INDUROT institute (University of Oviedo) has collected a sample of n1=133 birches, n2=109 sessile oaks and n3=37 rowans. Each tree was assigned a trapezoidal fuzzy number that models the experts subjective judgements/perceptions of the tree quality on a scale from 0 to 5 (0 meaning very bad quality to 5 meaning very good quality). Thereby the 1-cut is the interval in which the expert thinks the quality is contained and the support (0-cut) is the interval in which the expert is absolutely sure the quality is contained.

Usage

data("Trees")

Format

A list with three sublist, each of which contains trapezoidal fuzzy numbers.

Details

See Reference

References

[1] Colubi, A.: Statistical inference about the means of fuzzy random variables: Applications to the analysis of fuzzy- and real-valued data, Fuzzy Sets and Systems, 160(3), pp. 344-356 (2009)

Examples

data(Trees)
M<-Mmean(Trees[[1]],1)
M
sd<-sqrt(Bvar(Trees[[1]],1))
sd