s <- c(1,2,3)
result = matrix(0, nrow = max(s), ncol = length(s))
for (i in seq_along(s)) result[1:s[i], i] = 1
result
# [,1] [,2] [,3]
# [1,] 1 1 1
# [2,] 0 1 1
# [3,] 0 0 1
Сохранение строк как 1
s <- c(1,2,3)
result = matrix(0, nrow = sum(s), ncol = length(s))
result[cbind(1:sum(s), rep(seq_along(s), times = s))] = 1
result
# [,1] [,2] [,3]
# [1,] 1 0 0
# [2,] 0 1 0
# [3,] 0 1 0
# [4,] 0 0 1
# [5,] 0 0 1
# [6,] 0 0 1