> ## Documentation Index
> Fetch the complete documentation index at: https://docs.fiddler.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# CompareTo

> Comparison baseline types for alert rule thresholds.

Comparison baseline types for alert rule thresholds.

Determines what the current metric value should be compared against when
evaluating alert conditions.

## TIME\_PERIOD

Compare to a historical time period (relative comparison).
Useful for detecting changes over time, seasonal patterns, etc.
When using TIME\_PERIOD, the compare\_bin\_delta parameter specifies
how many time periods back to compare against.

## RAW\_VALUE

Compare to an absolute threshold value (absolute comparison).
Useful for hard limits and business rule enforcement.
When using RAW\_VALUE, compare\_bin\_delta is ignored.

<Warning>
  When using TIME\_PERIOD, the allowed compare\_bin\_delta values depend on bin\_size:
</Warning>

### Example

```python theme={null}
# Compare current hourly drift to same hour yesterday (24 hours ago)
alert_rule = AlertRule(
        compare_to=CompareTo.TIME_PERIOD,
        bin_size=BinSize.HOUR,
        compare_bin_delta=24  # 24 hours ago
    )

    # Compare daily metrics to last week (7 days ago)
    alert_rule = AlertRule(
            compare_to=CompareTo.TIME_PERIOD,
            bin_size=BinSize.DAY,
            compare_bin_delta=7  # 7 days ago
        )

        # Compare current accuracy to absolute minimum (no time comparison)
        alert_rule = AlertRule(
                compare_to=CompareTo.RAW_VALUE,
                threshold=0.85  # Must be above 85%
            )
```

## TIME\_PERIOD *= 'time\_period'*

## RAW\_VALUE *= 'raw\_value'*