---
title: "calculateW | JavaScript maps SDK"
description: "Documentation for MapTiler SDK"
---

> For AI agents: a documentation index is available at [/llms.txt](https://docs.maptiler.com/llms.txt). Markdown versions of all pages are available by appending .md to any URL.

# Function calculateW

-   calculateW(out: [quat](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.quat/), a: [ReadonlyQuat](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.ReadonlyQuat/)): [quat](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.quat/)[](#calculatew)
    
    Calculates the W component of a quat from the X, Y, and Z components. Assumes that quaternion is 1 unit in length. Any existing W component will be ignored.
    
    #### Parameters
    
    -   out: [quat](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.quat/)
        
        the receiving quaternion
        
    -   a: [ReadonlyQuat](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.ReadonlyQuat/)
        
        quat to calculate W component of
        
    
    #### Returns [quat](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.quat/)
    
    out