# `GSPath unitVectorAtNodeAtIndex:`

*Instance Method*

The tangent unit vector at a node index.

## Declaration

```objc
- (NSPoint) unitVectorAtNodeAtIndex:(NSInteger) nodeIdx;
```

```python
unitVectorAtNodeAtIndex_(nodeIdx: int) -> NSPoint
```

## Discussion

For the final node of an open path, the vector uses preceding nodes. Otherwise, the vector uses following nodes.

Returns a point whose x value is `NSNotFound` when no tangent can be determined.

## See Also

### Tangents

- [`GSPath tangentAngleAtNode:direction:`](/Core/GlyphsCore/GSPath/tangentAngleAtNode:direction:) — The tangent angle at a node.
- [`GSPath tangentAngleAtNodeAtIndex:direction:`](/Core/GlyphsCore/GSPath/tangentAngleAtNodeAtIndex:direction:) — The tangent angle at a node index.
- [`GSPath unitVectorAtNodeAtIndex:direction:`](/Core/GlyphsCore/GSPath/unitVectorAtNodeAtIndex:direction:) — The tangent unit vector at a node index.