a dataframe containing trait, genotype and environment.
trait
colname of a column containing a numeric vector of interested trait to be analysized.
genotype
colname of a column containing a character or factor vector labeling different genotypic varieties
environment
colname of a column containing a character or factor vector labeling different environments
unit.correct
logical, default is FALSE, returning the stability index with unit equals to squared unit of trait; when TRUE, returning stability index with the unit as same as unit of trait.
modify
logical, default is FALSE, returning the original ecovalence; when TRUE, returning modified ecovalence in consideration of number of environment.
Author
Tien-Cheng Wang
Details
Ecovalence (Wricke, 1962) is calcualted based on square and sum up the genotype–environment
interaction all over the environment.
Variety with low ecovalence is considered as stable.
Equation of ecovalence can be found in vignette file.