r语言中如何实现数据标准化(每一列的值除以该列均值)?答:使用apply函数apply(mat, 2, function(x)x/(mean(x)))测试运行结果:> ma <- matrix(c(1:4, 1, 6:8), nrow = 2)> ma [,1] [,2] [,3] [,4][1,] 1 3 1 7 [2,] 2 4 6 8 > apply(ma, 2, function(x)x/(mean(x)))[,1] [,2] ...
r语言如何求矩阵中某一列的总和答:方法一:colSums(A)方法二:apply(A,2,sum)> x<-matrix(c(1,1,2,1,2,3,4,1),4,2)> x [,1] [,2][1,] 1 2 [2,] 1 3 [3,] 2 4 [4,] 1 1 > length(which((x[,1]==1)))[1] 3 > length(which((x[,2]==1)))[1] 1 x[,1]==1判断是否为1,返回True...