# Help / Release / J 4.06 / i. Sparse Arguments

 i. Sparse Arguments initial writing: 2001-02-21last updated: 2001-04-12

The dyad i. now supports sparse arguments, as do verbs based on it:

For example:

```   v=: 1 3 5 7 9
] i =: v i. \$. i.2 3
0 1 | 0
0 2 | 5
1 0 | 1
1 1 | 5
1 2 | 2
\$.^:_1 i
5 0 5
1 5 2
(v i. i.2 3) -: v i. \$. i. 2 3
1
(\$.i.2 3) e. v
0 1 | 1
0 2 | 0
1 0 | 1
1 1 | 0
1 2 | 1

] x=: (i.3 4) * ?. 3 4\$2
0 1  0  3
0 0  6  7
8 0 10 11
\$. x
0 1 |  1
0 3 |  3
1 2 |  6
1 3 |  7
2 0 |  8
2 2 | 10
2 3 | 11
] i=: v i. \$. x
0 1 | 0
0 3 | 1
1 2 | 5
1 3 | 3
2 0 | 5
2 2 | 5
2 3 | 5
\$.^:_1 i
5 0 5 1
5 5 5 3
5 5 5 5
(v i. x) -: v i. \$. x
1

] d=: (?.13\$8) { (?.8\$2) * ?.8 3\$10
5 2 0
0 4 6
3 5 8
0 0 0
5 2 0
0 0 0
0 0 0
0 0 0
5 9 8
3 5 8
0 0 0
0 4 6
0 0 0
] s=: \$. d
0 0 | 5
0 1 | 2
1 1 | 4
1 2 | 6
2 0 | 3
2 1 | 5
2 2 | 8
4 0 | 5
4 1 | 2
8 0 | 5
8 1 | 9
8 2 | 8
9 0 | 3
9 1 | 5
9 2 | 8
11 1 | 4
11 2 | 6

s i. 0 0 0
3
s i: 0 0 0
12
s i. 5 9 8 , 0 4 6 ,: 999
0 |  8
1 |  1
2 | 13
s i. s
0 | 0
1 | 1
2 | 2
4 | 0
8 | 8
9 | 2
11 | 1
s i: s
0 |  4
1 | 11
2 |  9
4 |  4
8 |  8
9 |  9
11 | 11
3 \$. s i. s
3
3 \$. s i: s
12

d i. 0 0 0
3
d i: 0 0 0
12
d i. 5 9 8 , 0 4 6 ,: 999
8 1 13
d i. d
0 1 2 3 0 3 3 3 8 2 3 1 3
d i: d
4 11 9 12 4 12 12 12 8 9 12 11 12
```