Print a multiplication table with minimal code

2020-02-13 04:48发布

In R, what is the fastest way(shortest code) to print multiplication table? The functions seq rep and the bind functions help, but I'm looking for the shortest line(s) of code to do this.

rbind("1\'s"=1:12, "2\'s"=seq(2,24,2), "3\'s"=seq(3,36,3), 
      "4\'s"=seq(4,48,4), "5\'s"=seq(5,60,5), "6\'s"=seq(6,72,6))

Prints the 1's through 6's going across (horizontally). Anyone know how to perform this in a more compact way?

标签: r seq rbind
2条回答
萌系小妹纸
2楼-- · 2020-02-13 05:21

A shortcut for outer(1:6, 1:12, "*"):

> 1:6 %o% 1:12
     [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12]
[1,]    1    2    3    4    5    6    7    8    9    10    11    12
[2,]    2    4    6    8   10   12   14   16   18    20    22    24
[3,]    3    6    9   12   15   18   21   24   27    30    33    36
[4,]    4    8   12   16   20   24   28   32   36    40    44    48
[5,]    5   10   15   20   25   30   35   40   45    50    55    60
[6,]    6   12   18   24   30   36   42   48   54    60    66    72
查看更多
霸刀☆藐视天下
3楼-- · 2020-02-13 05:40
tbl <- outer(1:6, 1:12, "*")
rownames(tbl) <- paste(1:6, "'s", sep="")
tbl

You could make slightly more compact by using paste0(1:6, "'s")

This seems a slight improvement:

> v<-setNames(1:6, paste0(1:6, "\'s"))
> v %o% v
    1's 2's 3's 4's 5's 6's
1's   1   2   3   4   5   6
2's   2   4   6   8  10  12
3's   3   6   9  12  15  18
4's   4   8  12  16  20  24
5's   5  10  15  20  25  30
6's   6  12  18  24  30  36
查看更多
登录 后发表回答