r语言 如何匹配两个矩阵答:a <- 1:8a <- matrix(a,4,2)ab <- c(1:6,0,0)b <- matrix(b,4,2)bc <- a==bc#求一个向量表示行是不是相同apply(c,1,all)index <- apply(c,1,all)#只取相同的行a[index,]
R语言把大量记录型数据转换成矩阵答:dat1=data.frame(host=c("A","A","A","E","E","G"),guest=c("C","B","D","Q","F","W"),num=c(2,1,2,3,0,2))library(reshape)dat2=cast(dat1,host~guest,value="num")dat2
r语言 matrix(1,2,1)是什么意思答:matrix函数是R语言中base包里的矩阵函数,matrix(1,2,1) 用来创建一个2行1列数据都是1的矩阵。例如:> matrix(1,2,1);[,1][1,] 1 [2,] 1 > matrix(3,2,2);[,1] [,2][1,] 3 3 [2,] 3 3 > matrix(3,1,2);[,1] [,2][1,] 3 3 ...