《R语言介绍.ppt

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 4 Apply函数 不用Apply: get.mean=function(x) + { + report=rep(0,4) + for(i in 1:4) + report[i]=mean(x[,i]) + report + } data(iris) get.mean(iris) [1] 5.843333 3.057333 3.758000 1.199333 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd. 用Apply函数： get.mean(iris) [1] 5.843333 3.057333 3.758000 1.199333 apply(iris[,1:4],2,mean) Sepal.Length Sepal.Width Petal.Length Petal.Width 5.843333 3.057333 3.758000 1.199333 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd. 第五章 统计模型 1 回归模型 lm(因变量~自变量+自变量+…[-1]) data(faithful) attach(faithful) names(faithful) [1] eruptions waiting Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd. plot(eruptions, waiting) Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd. lm(waiting~eruptions) Call: lm(formula = waiting ~ eruptions) Coefficients: (Intercept) eruptions 33.47 10.73 lm(waiting~eruptions-1) Call: lm(formula = waiting ~ eruptions - 1) Coefficients: eruptions 19.40 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd. faithful.lm=lm(waiting~eruptions) summary(faithful.lm) Call: lm(formula = waiting ~ eruptions) Residuals: Min 1Q Median 3Q Max -12.0796 -4.4831 0.2122 3.9246 15.9719 Coefficients: Estimate Std. Error t value Pr(|t|) (Intercept) 33.4744 1.1549 28.98 2e-16 *** eruptions 10.7296 0.3148 34.09 2e-16 *** --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 Residual standard error: 5.914 on 270 degrees of freedom Multiple R-squared: 0.8115, Adjusted R-squared: 0.8108 F-statistic: 1162 on 1 and 270 DF, p-