Description Usage Arguments Details Value Author(s) References Examples
ammi_indexes()
computes several AMMIbased stability statistics. See
Details for a detailed overview.
1 2 3  ammi_indexes(.data, order.y = NULL, level = 0.95)
AMMI_indexes(.data, order.y = NULL, level = 0.95)

.data 
An object of class 
order.y 
A vector of the same length of 
level 
The confidence level. Defaults to 0.95. 
First, let's define some symbols: \mjseqnN' is the number of significant interation principal component axis (IPCs) that were retained in the AMMI model via F tests); \mjseqn\lambda_n is the singular value for th IPC and correspondingly \mjseqn\lambda_n^2 its eigen value; \mjseqn\gamma_in is the eigenvector value for ith genotype; \mjseqn\delta_jn is the eigenvector value for the th environment. \mjseqnPC_1, \mjseqnPC_2, and \mjseqnPC_n are the scores of 1st, 2nd, and nth IPC; respectively; \mjseqn\theta_1, \mjseqn\theta_2, and \mjseqn\theta_n are percentage sum of squares explained by the 1st, 2nd, and nth IPC, respectively.
\loadmathjaxAMMI Based Stability Parameter (ASTAB) (Rao and Prabhakaran 2005). \mjsdeqnASTAB = \sum_n=1^N'\lambda_n\gamma_in^2
AMMI Stability Index (ASI) (Jambhulkar et al. 2017) \mjsdeqnASI = \sqrt\left [ PC_1^2 \times \theta_1^2 \right ]+\left[ PC_2^2 \times \theta_2^2 \right ]
AMMIstability value (ASV) (Purchase et al., 2000). \mjsdeqnASV_i=\sqrt\fracSS_IPCA1SS_IPCA2(\mathrmIPC \mathrmA 1)^2+(\mathrmIPCA 2)^2
Sum Across Environments of Absolute Value of GEI Modelled by AMMI (AVAMGE) (Zali et al. 2012) \mjsdeqnAV_(AMGE) = \sum_j=1^E \sum_n=1^N' \left \lambda_n\gamma_in \delta_jn \right 
Annicchiarico's D Parameter values (Da) (Annicchiarico 1997) \mjsdeqnD_a = \sqrt\sum_n=1^N'(\lambda_n\gamma_in)^2
Zhang's D Parameter (Dz) (Zhang et al. 1998) \mjsdeqnD_z = \sqrt\sum_n=1^N'\gamma_in^2
Sums of the Averages of the Squared Eigenvector Values (EV) (Zobel 1994) \mjsdeqnEV = \sum_n=1^N'\frac\gamma_in^2N'
Stability Measure Based on Fitted AMMI Model (FA) (Raju 2002) \mjsdeqnFA = \sum_n=1^N'\lambda_n^2\gamma_in^2
Modified AMMI Stability Index (MASI) (Ajay et al. 2018) \mjsdeqnMASI = \sqrt \sum_n=1^N' PC_n^2 \times \theta_n^2
Modified AMMI Stability Value (MASV) (Ajay et al. 2019) \mjsdeqnMASV = \sqrt\sum_n=1^N'1\left (\fracSSIPC_nSSIPC_n+1 \right ) \times (PC_n)^2 + \left (PC_N'\right )^2
Sums of the Absolute Value of the IPC Scores (SIPC) (Sneller et al. 1997) \mjsdeqnSIPC = \sum_n=1^N'  \lambda_n^0.5\gamma_in
Absolute Value of the Relative Contribution of IPCs to the Interaction (Za) (Zali et al. 2012) \mjsdeqnZa = \sum_i=1^N'  \theta_n\gamma_in 
Weighted average of absolute scores (WAAS) (Olivoto et al. 2019) \mjsdeqnWAAS_i = \sum_k = 1^p IPCA_ik \times \theta_k/ \sum_k = 1^p\theta_k
For all the statistics, simultaneous selection indexes (SSI) are also computed by summation of the ranks of the stability and mean performance, Y_R, (Farshadfar, 2008).
A list where each element contains the result AMMIbased stability indexes for one variable.
Tiago Olivoto tiagoolivoto@gmail.com
Ajay BC, Aravind J, Abdul Fiyaz R, Bera SK, Kumar N, Gangadhar K, Kona P (2018). “Modified AMMI Stability Index (MASI) for stability analysis.” ICARDGR Newsletter, 18, 4–5.
Ajay BC, Aravind J, Fiyaz RA, Kumar N, Lal C, Gangadhar K, Kona P, Dagla MC, Bera SK (2019). “Rectification of modified AMMI stability value (MASV).” Indian Journal of Genetics and Plant Breeding (The), 79, 726–731. https://www.isgpb.org/article/rectificationofmodifiedammistabilityvaluemasv.
Annicchiarico P (1997). “Joint regression vs AMMI analysis of genotypeenvironment interactions for cereals in Italy.” Euphytica, 94(1), 53–62. doi: 10.1023/A:1002954824178
Farshadfar E (2008) Incorporation of AMMI stability value and grain yield in a single nonparametric index (GSI) in bread wheat. Pakistan J Biol Sci 11:1791–1796. doi: 10.3923/pjbs.2008.1791.1796
Jambhulkar NN, Rath NC, Bose LK, Subudhi HN, Biswajit M, Lipi D, Meher J (2017). “Stability analysis for grain yield in rice in demonstrations conducted during rabi season in India.” Oryza, 54(2), 236–240. doi: 10.5958/22495266.2017.00030.3
Olivoto T, LUcio ADC, Silva JAG, et al (2019) Mean Performance and Stability in MultiEnvironment Trials I: Combining Features of AMMI and BLUP Techniques. Agron J 111:2949–2960. doi: 10.2134/agronj2019.03.0220
Raju BMK (2002). “A study on AMMI model and its biplots.” Journal of the Indian Society of Agricultural Statistics, 55(3), 297–322.
Rao AR, Prabhakaran VT (2005). “Use of AMMI in simultaneous selection of genotypes for yield and stability.” Journal of the Indian Society of Agricultural Statistics, 59, 76–82.
Sneller CH, KilgoreNorquest L, Dombek D (1997). “Repeatability of yield stability statistics in soybean.” Crop Science, 37(2), 383–390. doi: 10.2135/cropsci1997.0011183X003700020013x
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.
Zhang Z, Lu C, Xiang Z (1998). “Analysis of variety stability based on AMMI model.” Acta Agronomica Sinica, 24(3), 304–309. http://zwxb.chinacrops.org/EN/Y1998/V24/I03/304.
Zobel RW (1994). “Stress resistance and root systems.” In Proceedings of the Workshop on Adaptation of Plants to Soil Stress. 14 August, 1993. INTSORMIL Publication 942, 80–99. Institute of Agriculture and Natural Resources, University of NebraskaLincoln.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17  library(metan)
model <
performs_ammi(data_ge,
env = ENV,
gen = GEN,
rep = REP,
resp = c(GY, HM))
model_indexes < ammi_indexes(model)
# Alternatively (and more intuitively) using %>%
# If resp is not declared, all traits are analyzed
res_ind < data_ge %>%
performs_ammi(ENV, GEN, REP, verbose = FALSE) %>%
ammi_indexes()
rbind_fill_id(res_ind, .id = "TRAIT")

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