AVAMGE.AMMI {ammistability} | R Documentation |

`AVAMGE.AMMI`

computes the Sum Across Environments of Absolute Value of
GEI Modelled by AMMI (AVAMGE)
(Zali et al. 2012) considering all significant
interaction principal components (IPCs) in the AMMI model. Using AVAMGE, the
Simultaneous Selection Index for Yield and Stability (SSI) is also calculated
according to the argument `ssi.method`

.

AVAMGE.AMMI(model, n, alpha = 0.05, ssi.method = c("farshadfar", "rao"), a = 1)

`model` |
The AMMI model (An object of class |

`n` |
The number of principal components to be considered for computation. The default value is the number of significant IPCs. |

`alpha` |
Type I error probability (Significance level) to be considered to identify the number of significant IPCs. |

`ssi.method` |
The method for the computation of simultaneous selection
index. Either |

`a` |
The ratio of the weights given to the stability components for
computation of SSI when |

The Sum Across Environments of Absolute Value of GEI Modelled by AMMI (\(AV_{(AMGE)}\)) (Zali et al. 2012) is computed as follows:

\[AV_{(AMGE)} = \sum_{j=1}^{E} \sum_{n=1}^{N'} \left |\lambda_{n} \gamma_{in} \delta_{jn} \right |\]Where, \(N'\) is the number of significant IPCs (number of IPC that were retained in the AMMI model via F tests); \(\lambda_{n}\) is the singular value for \(n\)th IPC and correspondingly \(\lambda_{n}^{2}\) is its eigen value; \(\gamma_{in}\) is the eigenvector value for \(i\)th genotype; and \(\delta{jn}\) is the eigenvector value for the \(j\)th environment.

A data frame with the following columns:

`AVAMGE` |
The AVAMGE values. |

`SSI` |
The computed values of simultaneous selection index for yield and stability. |

`rAVAMGE` |
The ranks of AVAMGE values. |

`rY` |
The ranks of the mean yield of genotypes. |

`means` |
The mean yield of the genotypes. |

The names of the genotypes are indicated as the row names of the data frame.

Zali H, Farshadfar E, Sabaghpour SH, Karimizadeh R (2012).
“Evaluation of genotype × environment interaction in chickpea using measures of stability from AMMI model.”
*Annals of Biological Research*, **3**(7), 3126–3136.

library(agricolae) data(plrv) # AMMI model model <- with(plrv, AMMI(Locality, Genotype, Rep, Yield, console = FALSE)) # ANOVA model$ANOVA # IPC F test model$analysis # Mean yield and IPC scores model$biplot # G*E matrix (deviations from mean) array(model$genXenv, dim(model$genXenv), dimnames(model$genXenv)) # With default n (N') and default ssi.method (farshadfar) AVAMGE.AMMI(model) # With n = 4 and default ssi.method (farshadfar) AVAMGE.AMMI(model, n = 4) # With default n (N') and ssi.method = "rao" AVAMGE.AMMI(model, ssi.method = "rao") # Changing the ratio of weights for Rao's SSI AVAMGE.AMMI(model, ssi.method = "rao", a = 0.43)

[Package *ammistability* version 0.1.2 Index]