diag
Syntax
diag(X)
Arguments
X is a numeric vector or a square matrix.
Details
- If X is a vector, return a diagonal matrix.
- If X is a square matrix, return a vector with the diagonal elements of the matrix.
Examples
diag(1..5);| #0 | #1 | #2 | #3 | #4 |
|---|---|---|---|---|
| 1 | 0 | 0 | 0 | 0 |
| 0 | 2 | 0 | 0 | 0 |
| 0 | 0 | 3 | 0 | 0 |
| 0 | 0 | 0 | 4 | 0 |
| 0 | 0 | 0 | 0 | 5 |
m=1..4$2:2;
m;| #0 | #1 |
|---|---|
| 1 | 3 |
| 2 | 4 |
diag(m);
// output: [1,4]