gge biplot双向作图软件方法解析.ppt

BIPLOT ANALYSIS OF AUTOMOBILE EVALUATION DATA Weikai Yan, Ph. D Email: wyan@ Web: Why biplot? “One picture is worth of 10,000 words.” Biplot is a very informative “picture” of research data Three types of biplot will be used in this study Automobile by parameter biplot Genotype by trait biplot in terms of agricultural studies (Yan and Rajcan 2002, Crop Science ) Automobile by judge biplot Genotype by environment biplot in terms of agricultural studies (Yan 2001, Agronomy Journal) parameter by judge biplot Genetic covariate by environment biplot (Yan and Tinker 2005, Crop Science) Car by parameter table Car by parameter biplot “Biplot” PC1 vs. PC2 (“Primary” biplot) Cars: blue parameters: red Four questions to ask before trying to interpret a biplot Mathematical model? Model =1 (parameter-centered data = GGE biplot) Goodness of fit? 64% S.V.P.? SVP = 1 (? = 1), car-metric preserving Axes drawn to scale? Always “Yes” by GGEbiplot Relationships among parameters Cosine of an angle between two parameters Correlation between two parameters Acute angles: Positive correlations Obtuse angles: Negative correlations Right angles: no correlation Vector length Discriminating ability of the parameter A short vector: Not related to any other parameters Lack of variation or not well represented in the biplot Biplot of PC3 vs. PC4 Display variations that are not displayed by the “primary” biplot of PC1 vs. PC2 To check if the primary biplot is adequate Rank cars based on any parameter“MPG” High: Civic_Honda Chvette_GMC … Low Firebird_GMC Rank cars based on any parameter“Ride” Rank cars based on any two parameters “MPG” and “RIDE” Rank cars on all parameters The parameter profile of any car: “Ford Continental” The parameter profile of any car:“Volvo DL” Compare any two cars:“Volvo DL” vs. “Continental” Which car gets the highest scoresfor what? Which car gets the lowest scoresfor what? Car by judge data(personal preference) Car by judge biplot Similarity among