modeling-app/docs/kcl/log.md

---
title: "log"
excerpt: "Compute the logarithm of the number with respect to an arbitrary base."
layout: manual
---

Compute the logarithm of the number with respect to an arbitrary base.

The result might not be correctly rounded owing to implementation details; `log2()` can produce more accurate results for base 2, and `log10()` can produce more accurate results for base 10.

```js
log(num: number, base: number) -> number
```

### Tags

* `math`


### Arguments

| Name | Type | Description | Required |
|----------|------|-------------|----------|
| `num` | `number` |  | Yes |
| `base` | `number` |  | Yes |

### Returns

`number` 


### Examples

```js
exampleSketch = startSketchOn("XZ")
  |> startProfileAt([0, 0], %)
  |> line([log(100, 5), 0], %)
  |> line([5, 8], %)
  |> line([-10, 0], %)
  |> close(%)

example = extrude(5, exampleSketch)
```

![Rendered example of log 0](data:image/png;base64,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