---
title: Comparing values from different buckets
description: Compare the value from the latest point to an average value stored in another bucket. This is useful when using the average value to calculate a threshold check.
url: https://docs.influxdata.com/influxdb/cloud/query-data/common-queries/compare-values/
estimated_tokens: 1532
product: InfluxDB Cloud (TSM)
version: cloud
---

# Comparing values from different buckets

This example uses [NOAA water sample data](/influxdb/cloud/reference/sample-data/#noaa-water-sample-data).

This example compares the value from the latest point to an average value stored in another bucket. This is useful when using the average value to calculate a [threshold check](/influxdb/cloud/monitor-alert/checks/create/#threshold-check).

The following query:

-   Uses [`range()`](/flux/v0/stdlib/universe/range/) to define a time range.
-   Gets the last value in the `means` bucket and compares it to the last value in the `noaa` bucket using [`last()`](/flux/v0/stdlib/universe/last/).
-   Uses [`join()`](/flux/v0/stdlib/universe/join/) to combine the results
-   Uses [`map()`](/flux/v0/stdlib/universe/map/) to calculate the differences

```js
means = from(bucket: "weekly_means")
    |> range(start: 2019-09-01T00:00:00Z)
    |> last()
    |> keep(columns: ["_value", "location"])

latest = from(bucket: "noaa")
    |> range(start: 2019-09-01T00:00:00Z)
    |> filter(fn: (r) => r._measurement == "average_temperature")
    |> last()
    |> keep(columns: ["_value", "location"])

join(tables: {mean: means, reading: latest}, on: ["location"])
    |> map(fn: (r) => ({r with deviation: r._value_reading - r._value_mean}))
```

### Example results

| location | _value_mean | _value_reading | deviation |
| --- | --- | --- | --- |
| coyote_creek | 79.82710622710623 | 89 | 9.172893772893772 |
| santa_monica | 80.20451339915374 | 85 | 4.79548660084626 |

[queries](/influxdb/cloud/tags/queries/)