# Return a Matrix with Upper Triangle as TRUE values in R Programming – upper.tri() Function

• Last Updated : 16 Jun, 2020

`upper.tri()` function in R Language is used to return a matrix of logical values with upper triangle as TRUE.

Syntax: upper.tri(x, diag)

Parameters:
x: Matrix object
diag: Boolean value to include diagonal

Example 1:

 `# R program to print the ``# upper triangle of a matrix`` ` `# Creating a matrix``mat <``-` `matrix(c(``1``:``9``), ``3``, ``3``, byrow ``=` `T)`` ` `# Calling upper.tri() Function``# Excluding diagonal elements``upper.tri(mat, diag ``=` `F)`

Output:

```      [, 1]  [, 2]  [, 3]
[1, ] FALSE  TRUE  TRUE
[2, ] FALSE FALSE  TRUE
[3, ] FALSE FALSE FALSE
```

Example 2:

 `# R program to print the ``# upper triangle of a matrix`` ` `# Creating a matrix``mat <``-` `matrix(c(``1``:``9``), ``3``, ``3``, byrow ``=` `T)`` ` `# Calling upper.tri() Function``# including diagonal elements``upper.tri(mat, diag ``=` `T)`

Output:

```      [, 1]  [, 2] [, 3]
[1, ]  TRUE  TRUE TRUE
[2, ] FALSE  TRUE TRUE
[3, ] FALSE FALSE TRUE
```
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