---
title: Normalize data with notebooks
description: Learn how to create a notebook that normalizes or cleans data to make it easier to work with.
url: https://docs.influxdata.com/influxdb/v2/tools/notebooks/clean-data/
estimated_tokens: 3263
product: InfluxDB OSS v2
version: v2
---

# Normalize data with notebooks

This page documents an earlier version of InfluxDB OSS. [InfluxDB 3 Core](/influxdb3/core/) is the latest stable version.

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For more information, see [Token hashing](/influxdb/v2/admin/tokens/#token-hashing).

Learn how to create a notebook that normalizes data. Data normalization is the process of modifying or cleaning data to make it easier to work with. Examples include adjusting numeric values to a uniform scale and modifying strings.

Walk through the following example to create a notebook that queries [NOAA NDBC sample data](/influxdb/v2/reference/sample-data/#noaa-ndbc-data), normalizes degree-based wind directions to cardinal directions, and then writes the normalized data to a bucket.

1. [Create a new notebook](/influxdb/v2/tools/notebooks/create-notebook/).
    
2. In the **Build a Query** cell:
    
    1. In the **FROM** column under **Sample**, select **NOAA National Buoy Data**.
    2. In the next **FILTER** column, select **\_measurement** from the drop-down list and select the **ndbc** measurement in the list of measurements.
    3. In the next **FILTER** column, select **\_field** from the drop-down list, and select the **wind\_dir\_degt** field from the list of fields.
3. Click after your **Build a Query** cell to add a new cell and select **Flux Script**.
    
4. In the Flux script cell:
    
    1. Define a custom function (`cardinalDir()`) that converts a numeric degree value to a cardinal direction (N, NNE, NE, etc.).
        
    2. Use `__PREVIOUS_RESULT__` to load the output of the previous notebook cell into the Flux script.
        
    3. Use [`map()`](/flux/v0/stdlib/universe/map/) to iterate over each input row, update the field key to `wind_dir_cardinal`, and normalize the `_value` column to a cardinal direction using the custom `cardinalDir()` function.
        
    4. Use [`to()`](/flux/v0/stdlib/influxdata/influxdb/to/) to write the normalized data back to InfluxDB. Specify an existing bucket to write to or [create a new bucket](/influxdb/v2/admin/buckets/create-bucket/).
        
        ```js
        import "array"
        
        cardinalDir = (d) => {
            _cardinal = if d >= 348.7 or d < 11.25 then "N"
            else if d >= 11.25 and d < 33.75 then "NNE"
            else if d >= 33.75 and d < 56.25 then "NE"
            else if d >= 56.25 and d < 78.75 then "ENE"
            else if d >= 78.75 and d < 101.25 then "E"
            else if d >= 101.25 and d < 123.75 then "ESE"
            else if d >= 123.75 and d < 146.25 then "SE"
            else if d >= 146.25 and d < 168.75 then "SSE"
            else if d >= 168.75 and d < 191.25 then "S"
            else if d >= 191.25 and d < 213.75 then "SSW"
            else if d >= 213.75 and d < 236.25 then "SW"
            else if d >= 236.25 and d < 258.75 then "WSW"
            else if d >= 258.75 and d < 281.25 then "W"
            else if d >= 281.25 and d < 303.75 then "WNW"
            else if d >= 303.75 and d < 326.25 then "NW"
            else if d >= 326.25 and d < 348.75 then "NNW"
            else ""
        
            return _cardinal
        }
        
        __PREVIOUS_RESULT__
            |> map(fn: (r) => ({r with
                _field: "wind_dir_cardinal",
                _value: cardinalDir(d: r._value),
            }))
            |> to(bucket: "example-bucket")
        ```
        
5. Click after your **Flux Script** cell to add a new cell and select **Output to Bucket**. Select a bucket from the **Choose a bucket** drop-down list.
    
6. *(Optional)* Click and select **Note** to add a cell containing notes about what this notebook does. For example, the cell might say, “This notebook converts decimal degree wind direction values to cardinal directions.”
    
7. Click **Preview** in the upper left to verify that your notebook runs and previews the output.
    
8. Click **Run** to run the notebook and write the normalized data to your bucket.
    

## Continuously run a notebook

To continuously run your notebook, export the notebook as a task:

1. Click to add a new cell and then select **Task**.
    
2. Provide the following:
    
    -   **Every**: Interval that the task should run at.
    -   **Offset**: *(Optional)* Time to wait after the defined interval to execute the task. This allows the task to capture late-arriving data.
3. Click **Export as Task**.
    

[notebooks](/influxdb/v2/tags/notebooks/)