# forge.ta.variance

```python
forge.ta.variance(source: ArrayLike, period: int = 20) -> np.ndarray
```

Variance: the mean squared distance of the last ``period`` values from their average.

Since Forge API 1.

## Class forge.ta.Variance

```python
forge.ta.Variance(**inputs: Any) -> None
```

The square of the standard deviation over a period.

The mean squared distance of the last period values from their simple average.

Since Forge API 1.