如何按列查找矩阵列表的最小值

Question

假设我有一个矩阵列表。进一步假设我想在矩阵的每个值中找到最小值。例如，

Mysql

预期输出：

y <- c(3,2,4,5,6, 4,5,5,6,7)
x[lower.tri(x,diag=F)] <- y
> x
     [,1] [,2] [,3] [,4] [,5]
[1,]    0    0    0    0    0
[2,]    3    0    0    0    0
[3,]    2    6    0    0    0
[4,]    4    4    5    0    0
[5,]    5    5    6    7    0



k <- c(1,4,5,2,5,-4,4,4,4,5)
z[lower.tri(z,diag=F)] <- k
> z
     [,1] [,2] [,3] [,4] [,5]
[1,]    0    0    0    0    0
[2,]    1    0    0    0    0
[3,]    4    5    0    0    0
[4,]    5   -4    4    0    0
[5,]    2    4    4    5    0



 d <- list(k, x)

Answer 1

我们可以使用pmin为list

中的每个元素获取相应的最小值

do.call(pmin, d)
#     [,1] [,2] [,3] [,4] [,5]
#[1,]    0    0    0    0    0
#[2,]    1    0    0    0    0
#[3,]    2    5    0    0    0
#[4,]    4   -4    4    0    0
#[5,]    2    4    4    5    0

数据

d <- list(z, x)