stability.tai {agrostab}

R Documentation

Tai's stability analysis

Description

This function calculates the Tai's stability parameters.

Usage

stability.tai(dataf, res_var, gen_var, env_var, rep_var, plotIt = TRUE)

Arguments

dataf	the name of the data frame containing the data to analyze.
res_var	the response variable.
gen_var	the genotypes variable.
env_var	the environments variable.
rep_var	the replications variable.
plotIt	a logical value specifying if plot should be drawn; default is TRUE

Value

Returns a list of two objects:

ANOVA

the analysis of variance table

scores

the data frame object of stability analysis results:

• alpha regression of genotype means on environmental means

• t_value t-values for gypothesis that alpha=0

• p_value p-values for gypothesis that alpha=0

• lambda deviation from linear responses

• pf_value p-values for gypothesis that lambda=0

References

Tai, G.C.C. 1971. Genotypic stability analysis and application to potato regional trials. Crop Sci. 11: 184-190. doi:10.2135/cropsci1971.0011183X001100020006x

Examples

data(exp_data)
stability.tai(exp_data,"yield","gen","env","rep")

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