ge_polar: Power Law Residuals as yield stability index \loadmathjax

In metan: Multi Environment Trials Analysis

Power Law Residuals as yield stability index \loadmathjax

Description

Performs a stability analysis based on the Power Law Residuals (POLAR) statistics (Doring et al., 2015). POLAR is the residuals from the linear regression of \mjseqnlog(\sigma^2) against \mjseqnlog(\mu) and can be used as a measure of crop stability with lower stability (relative to all samples with that mean yield) indicated by more positive POLAR values, and higher stability (relative to all samples with that mean yield) indicated by more negative POLAR values.

Usage

ge_polar(.data, env, gen, resp, base = 10, verbose = TRUE)

Arguments

.data	The dataset containing the columns related to Environments, Genotypes and response variable(s).
env	The name of the column that contains the levels of the environments.
gen	The name of the column that contains the levels of the genotypes.
resp	The response variable(s). To analyze multiple variables in a single procedure use, for example, resp = c(var1, var2, var3).
base	The base with respect to which logarithms are computed. Defaults to 10.
verbose	Logical argument. If verbose = FALSE the code will run silently.

Value

An object of class ge_acv, which is a list containing the results for each variable used in the argument resp. For each variable, a tibble with the following columns is returned.

• GEN the genotype's code.

• POLAR The Power Law Residuals

• POLAR_R The rank for the ACV value.

Author(s)

Tiago Olivoto [e-mail]

References

Doring, T.F., S. Knapp, and J.E. Cohen. 2015. Taylor's power law and the stability of crop yields. F. Crop. Res. 183: 294-302. doi: 10.1016/j.fcr.2015.08.005

Examples

library(metan)
out <- ge_polar(data_ge2, ENV, GEN, c(EH, PH, EL, CD, ED, NKE))
gmd(out)

metan documentation built on March 7, 2023, 5:34 p.m.