# forge.ta.barssince

```python
forge.ta.barssince(condition: ArrayLike) -> np.ndarray
```

How many bars ago the condition last held: 0 on a bar where it holds.

Before the first bar where it holds there is no value. A number array counts as true where it is
not 0, so an event array works too. Example: ``ta.barssince(ta.crossover(fast, slow))``.

Since Forge API 1.