# Why Matrix MultiplyInplace is not BXA?

**URL:** <https://forum.babylonjs.com/t/why-matrix-multiplyinplace-is-not-bxa/49400>\
**Category:** Questions\
**Created:** [April 6, 2024, 12:25pm UTC](https://forum.babylonjs.com/t/why-matrix-multiplyinplace-is-not-bxa/49400 "2024-04-06T12:25:10Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![Moriy](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/moriy/32/30563_2.png) [@Moriy](https://forum.babylonjs.com/u/Moriy)\
**Post date:** [April 6, 2024, 12:25pm UTC](https://forum.babylonjs.com/t/why-matrix-multiplyinplace-is-not-bxa/49400/1 "2024-04-06T12:25:10Z")

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Function in core

 ![image](https://us1.discourse-cdn.com/flex024/uploads/babylonjs/original/3X/0/4/043600a2d874f1fb89b699300d7cb24c3b5ab2d4.png)

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**Author:** ![Deltakosh](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/deltakosh/32/26635_2.png) [@Deltakosh](https://forum.babylonjs.com/u/Deltakosh)\
**Post date:** [April 6, 2024, 10:17pm UTC](https://forum.babylonjs.com/t/why-matrix-multiplyinplace-is-not-bxa/49400/2 "2024-04-06T22:17:21Z")

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Sorry can you elaborate? I do not understand your question

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<div class="post-metadata">

**Author:** ![Moriy](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/moriy/32/30563_2.png) [@Moriy](https://forum.babylonjs.com/u/Moriy)\
**Post date:** [April 7, 2024, 1:10am UTC](https://forum.babylonjs.com/t/why-matrix-multiplyinplace-is-not-bxa/49400/3 "2024-04-07T01:10:22Z")

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Oh sorry my mistake. why multiply and multiplyToRef is B X A, and multiplyInPlace and MultiplyByFloats is multiply per number.

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<div class="post-metadata">

**Author:** ![Deltakosh](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/deltakosh/32/26635_2.png) [@Deltakosh](https://forum.babylonjs.com/u/Deltakosh)\
**Post date:** [April 7, 2024, 2:50pm UTC](https://forum.babylonjs.com/t/why-matrix-multiplyinplace-is-not-bxa/49400/4 "2024-04-07T14:50:11Z")

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That was a choice I made that seemed clever at that time:) There is no specific reason besides that:)

We should maybe mention it in the documentation though

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**Author:** ![Evgeni\_Popov](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/evgeni_popov/32/4432_2.png) [@Evgeni\_Popov](https://forum.babylonjs.com/u/Evgeni_Popov)\
**Post date:** [April 8, 2024, 8:35am UTC](https://forum.babylonjs.com/t/why-matrix-multiplyinplace-is-not-bxa/49400/5 "2024-04-08T08:35:57Z")

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In fact, `multiplyInPlace` and `multiplyByFloats` for the `Matrix` class are new in 7.0. It’s part of the math class rewrite, and these methods have been added to `Matrix` for consistency with other classes.

I will update the doc to make it clear they do a component by component multiplication.

[EDIT] PR:

> <https://github.com/BabylonJS/Babylon.js/pull/14954>

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<div class="post-metadata">

**Author:** ![Moriy](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/moriy/32/30563_2.png) [@Moriy](https://forum.babylonjs.com/u/Moriy)\
**Post date:** [April 8, 2024, 12:16pm UTC](https://forum.babylonjs.com/t/why-matrix-multiplyinplace-is-not-bxa/49400/6 "2024-04-08T12:16:40Z")

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Looking forward to publishing of Babylonjs 7.0!!!