Eberhart and Russell's regression model

Regression-based stability analysis using the Eberhart and Russell (1966) model.

Usage

ge_reg(.data, env, gen, rep, resp, verbose = TRUE)

Arguments

.data: The dataset containing the columns related to Environments, Genotypes, replication/block 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.
rep: The name of the column that contains the levels of the replications/blocks
resp: The response variable(s). To analyze multiple variables in a single procedure use, for example, resp = c(var1, var2, var3).
verbose: Logical argument. If verbose = FALSE the code will run silently.

Value

An object of class ge_reg with the folloing items for each variable:

data: The data with means for genotype and environment combinations and the environment index
anova: The analysis of variance for the regression model.
regression: A data frame with the following columns: GEN, the genotypes; b0 and b1 the intercept and slope of the regression, respectively; t(b1=1) the calculated t-value; pval_t the p-value for the t test; s2di the deviations from the regression (stability parameter); F(s2di=0) the F-test for the deviations; pval_f the p-value for the F test; RMSE the root-mean-square error; R2 the determination coefficient of the regression.
b0_variance: The variance of b0.
b1_variance: The variance of b1.

References

Eberhart, S.A., and W.A. Russell. 1966. Stability parameters for comparing Varieties. Crop Sci. 6:36-40. doi:10.2135/cropsci1966.0011183X000600010011x

Author

Tiago Olivoto, tiagoolivoto@gmail.com

Examples

# \donttest{
library(metan)
reg <- ge_reg(data_ge2,
             env = ENV,
             gen = GEN,
             rep = REP,
             resp = PH)
#> Evaluating trait PH |============================================| 100% 00:00:01 

plot(reg)


# }