要根据 R 数据框中的两个因素找到数值列的均值表，我们可以按照以下步骤操作 -
首先，创建一个包含两个因子和一个数值列的数据框。
然后，使用tapply函数根据因子列找到数值列的均值表。
让我们创建一个数据框，如下所示 -
Group1<-sample(c("I","II","III"),25,replace=TRUE)
Group2<-sample(c("Low","Medium","High"),25,replace=TRUE)
Score<-sample(1:100,25)
df<-data.frame(Group1,Group2,Score)
df执行时，上述脚本生成以下内容output(this output will vary on your system due to randomization)-
输出结果
Group1 Group2 Score 1 III Low 3 2 II High 45 3 III Medium 17 4 III Low 50 5 I Medium 40 6 III Low 77 7 II Medium 1 8 I High 73 9 II High 62 10 I High 5 11 II Medium 88 12 I High 98 13 I Medium 60 14 II Low 84 15 III Low 12 16 I Medium 66 17 III Medium 23 18 II High 61 19 I High 15 20 III High 94 21 II Medium 87 22 II Medium 37 23 I Medium 11 24 I High 26 25 I Medium 93
使用带有均值函数的 tapply 函数来查找基于 Group1 和 Group2 列的 Score 列的均值 -
Group1<-sample(c("I","II","III"),25,replace=TRUE)
Group2<-sample(c("Low","Medium","High"),25,replace=TRUE)
Score<-sample(1:100,25)
df<-data.frame(Group1,Group2,Score)
tapply(Score,list(df$Group1,df$Group2),mean)输出结果High Low Medium I 43.4 NA 54.00 II 56.0 84.0 53.25 III 94.0 35.5 20.00
让我们创建一个数据框，如下所示 -
f1<-sample(c("Male","Female"),25,replace=TRUE)
f2<-sample(c("Slow","Fast"),25,replace=TRUE)
Result<-sample(1:100,25)
dat<-data.frame(f1,f2,Result)
dat执行时，上述脚本生成以下内容output(this output will vary on your system due to randomization)-
输出结果
f1 f2 Result 1 Male Slow 37 2 Male Fast 13 3 Female Fast 87 4 Male Slow 36 5 Male Fast 22 6 Female Fast 86 7 Male Slow 42 8 Female Fast 17 9 Female Slow 46 10 Male Fast 27 11 Female Fast 49 12 Male Slow 24 13 Male Fast 53 14 Male Fast 67 15 Female Fast 28 16 Male Fast 6 17 Female Slow 61 18 Male Slow 90 19 Male Fast 12 20 Male Fast 47 21 Female Fast 9 22 Female Fast 66 23 Male Fast 73 24 Male Slow 14 25 Female Fast 81
使用带有均值函数的 tapply 函数根据 f1 和 f2 列查找结果列的均值 -
f1<-sample(c("Male","Female"),25,replace=TRUE)
f2<-sample(c("Slow","Fast"),25,replace=TRUE)
Result<-sample(1:100,25)
dat<-data.frame(f1,f2,Result)
tapply(Result,list(dat$f1,dat$f2),mean)输出结果Fast Slow Female 52.87500 53.5 Male 35.55556 40.5