Listy Biometryczne-Biometrical Letters Vol.36(2), 1999, pp.137-143
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L2 ENVIRONMENTAL INDEXES*
Joao Tiago Mexia1, Dulce Pereira2 and José Baeta3 1Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2825 Monte da Caparica, Portugal 2Universidade de Évora, 7000 Évora, Portugal 3Estaç?o Agronómica Nacional, 2780 Oeiras, Portugal |
The use of L2 norm in defining environmental indexes is discussed. For each type of L2 indexes a different type of regression of yield on environmental index is considered. The indexes are chosen in order to minimize the sum of the sums of squares of residuals for the regressions, there being a regression per variety. The special cases of linear and cubic indexes are singled out as well as the general polynomial case. The first of these cases constitutes an alternative to the classical Joint Regression Analysis in which the environmental indexes of the different blocks are their average yields.
L2 norm, environmental indexes, joint regression analysis
*The paper was submitted on the occasion of 70-th birthday of Professor Tadeusz Caliński
*The paper was submitted on the occasion of 70-th birthday of Professor Tadeusz Caliński
