toolStability (version 0.1.2)

stability_variance: Stability variance

Description

stability_variance calculate variance of a genotype across environments.

Usage

stability_variance(data, trait, genotype, environment, unit.correct = FALSE)

Value

a data table with stability variance

Arguments

data

a dataframe containing trait, genotype and environment.

trait

colname of a column containing a numeric vector of interested trait to be analyzed.

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.#'

Author

Tien-Cheng Wang

Details

Stability variance (Shukla, 1972) is calculatd based on lindear combination of ecovalence and mean square of genotype-environment interaction. Variety with low stability variance is considered as stable. Negative values of stability variance is replaced with 0. Equation of stability variance can be found in vignette file.

References

shukla1972toolStability

Examples

data(Data)
stability.variance <- stability_variance(
 data = Data,
 trait = "Yield",
 genotype = "Genotype",
 environment = "Environment")