通过列名和行名合并两个矩阵

由一起疯了发布于 2020-05-09 12:53:24

我想根据列名和行名合并两个矩阵。

两个矩阵中的值都是数字，并且合并是对同时出现的两个矩阵求平均值。

矩阵1：

和matrix2：

所以输出将是：

   A   B   C  D
x 3.5  4   2  2
y  2   3   1  3
z  3   3  2.5 4
k  4  3.5  3  1

My idea is to use for loop or apply function, but if the matrices are big, then this program will run for a long time. Any advice? Thank you!

wfuga

2020-05-09 12:53:24

You can use rownames and colnames to subset matrix2 and update only part of it.

matrix2[rownames(matrix1), colnames(matrix1)] <- (matrix1 + matrix2[rownames(matrix1), colnames(matrix1)])/2

matrix2

#    A   B   C D
#x 3.5 4.0 2.0 2
#y 2.0 3.0 1.0 3
#z 3.0 3.0 2.5 4
#k 4.0 3.5 3.0 1

数据

matrix1 <- structure(c(1L, 5L, 1L, 4L, 2L, 2L, 3L, 4L, 3L), .Dim = c(3L, 
           3L), .Dimnames = list(c("x", "z", "k"), c("A", "B", "C")))

matrix2 <- structure(c(6L, 2L, 1L, 7L, 4L, 3L, 4L, 5L, 1L, 1L, 1L, 3L, 2L, 
3L, 4L, 1L), .Dim = c(4L, 4L), .Dimnames = list(c("x", "y", "z", 
"k"), c("A", "B", "C", "D")))

一起疯了

这家伙很懒，什么都没留下

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