Triu

## triu(input, diagonal=0, out=NULL) -> Tensor

Returns the upper triangular part of a matrix (2-D tensor) or batch of matrices
`input`

, the other elements of the result tensor `out`

are set to 0.

The upper triangular part of the matrix is defined as the elements on and above the diagonal.

The argument `diagonal`

controls which diagonal to consider. If
`diagonal`

= 0, all elements on and above the main diagonal are
retained. A positive value excludes just as many diagonals above the main
diagonal, and similarly a negative value includes just as many diagonals below
the main diagonal. The main diagonal are the set of indices
\(\lbrace (i, i) \rbrace\) for \(i \in [0, \min\{d_{1}, d_{2}\} - 1]\) where
\(d_{1}, d_{2}\) are the dimensions of the matrix.

## Examples

```
if (torch_is_installed()) {
a = torch_randn(c(3, 3))
a
torch_triu(a)
torch_triu(a, diagonal=1)
torch_triu(a, diagonal=-1)
b = torch_randn(c(4, 6))
b
torch_triu(b, diagonal=1)
torch_triu(b, diagonal=-1)
}
#> torch_tensor
#> -1.6846 -0.2879 0.8049 0.1860 0.1675 1.6598
#> 1.5531 -0.7697 2.0431 -0.0344 1.3097 -0.6162
#> 0.0000 -1.3456 0.3866 0.2095 0.4716 0.6042
#> 0.0000 0.0000 -1.2135 -0.1067 -0.2139 -0.8899
#> [ CPUFloatType{4,6} ]
```