用 NA 填充两个矩阵的缺失数据

我有两个方阵，其中都有一些缺失的数据。我想在两个矩阵中用 NA 填充缺失的数据

数据如下：

#first matrix
t1 = matrix(
  c(1, 0, 1, 0, 0, 1, 1, 0, 1),
  nrow = 3,  
  ncol = 3,        
  byrow = TRUE         
)
rownames(t1) <- c("a","b", "c")
colnames(t1) <- c("a","b", "c")

#second matrix
t2 = matrix(
  c(1, 1, 0, 0, 0, 1, 0, 0, 1),
  nrow = 3,  
  ncol = 3,        
  byrow = TRUE         
)
rownames(t2) <- c("a","c", "d") 
colnames(t2) <- c("a","c", "d")
#Expected outcome for the two matrices:
#first matrix
  a  b  c  d
a 1  0  1  NA
b 0  0  1  NA
c 1  0  1  NA
d NA NA NA NA

#second matrix
  a  b  c  d
a 1  NA 1  0
b NA NA NA NA
c 0  NA 0  1
d 0  NA 0  1

我该如何实现这一目标？优选地，结果是包含这两个 NA 填充矩阵的列表

如果每个矩阵中的行和列名称始终相同（此处没有硬编码的行/列名称）：

nam <- union(rownames(t1), rownames(t2))
m <- array(dim=rep(length(nam), 2),
           dimnames=list(nam, nam))
lapply(list(t1, t2), function(x) {
  m[rownames(x), colnames(x)] <- x
  m
})

# [[1]]
#    a  b  c  d
# a  1  0  1 NA
# b  0  0  1 NA
# c  1  0  1 NA
# d NA NA NA NA
# 
# [[2]]
#    a  b  c  d
# a  1 NA  1  0
# b NA NA NA NA
# c  0 NA  0  1
# d  0 NA  0  1