# diagonal

`import { diagonal } from "destack:tensor";`

Return the diagonal of a matrix.

```ds title="diagonal"
export function diagonal<T>(matrix: Tensor<T, 2>, options?: TensorOutputOptions<T, 1> | undefined): Tensor<T, 1>
```

[language/library/src/tensor/linalg.ds:47:52](https://github.com/destack-sh/destack/blob/main/language/library/src/tensor/linalg.ds#L47-L52)