triu

Syntax

triu(X, [k=0])

Arguments

X is a matrix.

k is an integer.

Details

If k is not specified: return the upper triangular portion of matrix X.

If k is specified: return the elements on and above the k-th diagonal of X.

This function was released in version 1.30.0.

Examples

$ m=matrix(1 2 3, 4 5 6, 7 8 9);
$ m;

col1

col2

col3

1

4

7

2

5

8

3

6

9

$ triu(m);

col1

col2

col3

1

4

7

0

5

8

0

0

9

$ triu(m,1);

col1

col2

col3

0

4

7

0

0

8

0

0

0

$ triu(m,-1);

col1

col2

col3

1

4

7

2

5

8

0

6

9

Related function: tril