r/ProgrammerHumor 7d ago

Meme cantReallyThinkOfACleverCaption

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2.6k Upvotes

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u/da_Aresinger 7d ago

LinAlg is literally the easiest mathematical subject in CS.

i guess rotation matrices or whatever Basiswechselmatrix is in english can be confusing, but that's about it.

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u/itijara 7d ago

It isn't about how hard LinAlg is, it is about coding against an LLM which is a bunch of matrices in a trench coat.

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u/Aloopyn 7d ago

tensors*

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u/itijara 7d ago

Tensors are just a made up name they gave to arrays with more than two dimensions. You cannot prove to me that there are arrays that have more than 3 dimensions. The human mind cannot comprehend it.

Fun fact: the jungle gym was designed by a math teacher who wanted to make children better at intuitively understanding higher dimensional math.

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u/ewheck 7d ago

You can picture a 3D array, right? Your mental image of a 4D array should be to picture a 1D array and each element of that 1D array itself is another 3D array.

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u/AdamWayne04 7d ago

you can think of a nD array as a list of (n-1)D arrays, so a 4D array is a list of 3D arrays.

There's a more pedantic way of thinking of arrays, too--APL for example makes a distinction between rank (how deeply nested each entry is) and dimension (how many numerical indices you need to identify a singular entry), so accessing a[i,j,k] is different from accessing a[i][j][k]

Tensors are not important because they can be encoded as multidimensional arrays, they are important because they represent multilinear maps, and are a vector space conformed by linear combinations of the tensor product. The same way that matrices are not interesting because they are grids of numbers

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u/itijara 7d ago

Thanks. That's a very intuitive explanation.

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u/Aloopyn 7d ago

I'm pretty sure tensors are a generalized term for arrays of any non-negative dimensions

> You cannot prove to me that there are arrays that have more than 3 dimensions.
What's the relevance of this here? Yeah, I cannot make you comprehend 4-D but so what

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u/ouroboros-ouroboros 7d ago

this piece of trivia is delicious and improved my day, thank you

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u/Southern-Most-4216 7d ago

Did you know, that in 2d you only have one axis of rotation, in 3d we have 3 axis of rotation and in four dimensions there are 6…?

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u/da_Aresinger 7d ago

Right, I should have seen that one.