---
title: "multiplyScalarAndAdd | 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 multiplyScalarAndAdd

-   multiplyScalarAndAdd(  
        out: [mat4](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.mat4/),  
        a: [ReadonlyMat4](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.ReadonlyMat4/),  
        b: [ReadonlyMat4](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.ReadonlyMat4/),  
        scale: number,  
    ): [mat4](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.mat4/)[](#multiplyscalarandadd)
    
    Adds two mat4's after multiplying each element of the second operand by a scalar value.
    
    #### Parameters
    
    -   out: [mat4](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.mat4/)
        
        the receiving vector
        
    -   a: [ReadonlyMat4](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.ReadonlyMat4/)
        
        the first operand
        
    -   b: [ReadonlyMat4](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.ReadonlyMat4/)
        
        the second operand
        
    -   scale: number
        
        the amount to scale b's elements by before adding
        
    
    #### Returns [mat4](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.mat4/)
    
    out