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Tensors (mander.xyz)
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The difference between a matrix and a 2d array of numbers is the operations that are performed

A tensor really isn't standardized in the same way so it's basically just an n-d array in my mind

[-] leisesprecher@feddit.org 29 points 2 months ago

It's all just pointers with semantics attached.

[-] socsa@piefed.social 8 points 2 months ago

Vectors with strides.

[-] ZILtoid1991@lemmy.world 3 points 2 months ago

You can force a 2D array to be a matrix if you're clever enough

[-] azi@mander.xyz 2 points 2 months ago

good ol' nominal typing

[-] Hawk@lemmynsfw.com 2 points 2 months ago

Well, it would still be a vector. So some standardisation.

[-] muntedcrocodile@lemm.ee 27 points 2 months ago

Everything's a matrix if u fuck with it hard enough

[-] ignotum@lemmy.world 8 points 2 months ago

Everything's a matrix if you realize there is no spoon

[-] UnRelatedBurner@sh.itjust.works 5 points 2 months ago

Sadly, they patched the spoon exploit.

[-] ZILtoid1991@lemmy.world 3 points 2 months ago

You can still use movd, movq, movups, etc.

[-] mumblerfish@lemmy.world 15 points 2 months ago

A tensor is something that transform as a tensor. Gtfo Christoffel symbols.

[-] vzq@lemmy.blahaj.zone 6 points 2 months ago

Duck typing ftw

[-] marcos@lemmy.world 13 points 2 months ago

How you describe a thing is different from what a thing is... A tensor is not a matrix.

And on mathematics, "what a thing is" is a completely useless concept... So, it makes no difference whatsoever.

[-] affiliate@lemmy.world 0 points 2 months ago

the "categorical" way of defining tensor products is essentially "that thing that lets you turn multi-linear maps into linear maps", and linear maps (of finite dimensional vector spaces) are basically matrices anyways. so i don't see it as much of a stretch to say tensors are matrices.

(can you tell that i never took a physics class?)

[-] tatterdemalion@programming.dev 7 points 2 months ago* (last edited 2 months ago)

Square matrices are linear endomorphisms. They are isomorphic to (1,1) tensors but not any other rank of tensors.

[-] affiliate@lemmy.world 3 points 2 months ago

a tensor is a multi-linear map V × ... × V × V^^ × ... × V^^ → F, and a multi-linear map V × ... × V × V^^ × ... × V^^ → F is the same as a linear map V ⊗ ... ⊗ V ⊗ V^^ ⊗ ... ⊗ V^^ → F. and a linear map is ""the same thing as"" a matrix. so in this way, you can associate matrices to tensors. (but the matrices are formed in the tensor space V ⊗ ... ⊗ V ⊗ V^^ ⊗ ... ⊗ V^^, not in the vector space V.)

this post was submitted on 03 Sep 2024
202 points (94.3% liked)

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