stability_variance {toolStability}

Stability variance

Description

stability_variance calculate variance of a genotype across environments.

Usage

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

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.#'

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.

Value

a data table with stability variance

Author(s)

Tien-Cheng Wang

References

Shukla GK (1972). “Some statistical aspects of partitioning genotype environmental components of variability.” Heredity, 29(2), 237–245.

Examples

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