head
Syntax
head(X, [n=1])
Arguments
X is a vector/matrix/table.
n (optional) is a positive integer. The default value is 1.
Details
Return the first n element(s) of a vector, or the first n columns of a matrix, or the first n rows of a table.
Examples
x=1..10;
head(x);
// output
1
x=1..10$2:5;
x;| #0 | #1 | #2 | #3 | #4 |
|---|---|---|---|---|
| 1 | 3 | 5 | 7 | 9 |
| 2 | 4 | 6 | 8 | 10 |
x.head();
// output
[1,2]
head(x,2);| #0 | #1 |
|---|---|
| 1 | 3 |
| 2 | 4 |
x=table(1..5 as a, 6..10 as b);
x;| a | b |
|---|---|
| 1 | 6 |
| 2 | 7 |
| 3 | 8 |
| 4 | 9 |
| 5 | 10 |
head(x);
// output
b->6
a->1
x.head(2);| a | b |
|---|---|
| 1 | 6 |
| 2 | 7 |
Related function: tail