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

# Logarithm

> Calculate a natural logarithm or a logarithm in a chosen base.

The **Logarithm** action calculates the exponent to which a base must be raised
to produce the input number. Leave **Base** empty for the natural logarithm.

## Inputs

| Input      | Type   | Required | Description                                         |
| ---------- | ------ | -------- | --------------------------------------------------- |
| **Number** | Number | Yes      | A non-negative value whose logarithm is calculated. |
| **Base**   | Number | No       | The logarithm base. Defaults to `e`.                |

## Outputs

| Output  | Type   | Description                         |
| ------- | ------ | ----------------------------------- |
| **Log** | Number | The logarithm in the selected base. |

For example, **Number** `1000` with **Base** `10` returns approximately `3`.

<Warning>
  Although zero is accepted, its logarithm is negative infinity. Bases `1`, `0`,
  and negative values can produce infinity or `NaN`; use a positive base other
  than `1` for ordinary real-number logarithms.
</Warning>