Comment on Vectors Part 2
MadhuGururajan@programming.dev 3 months agoIts easy to think about vectors in the first sense (as anything with direction and magnitude) when we’re working with classical units (space, force, electric fields, etc)
But it becomes a nightmare to understand intuitively when the vector is defined as something with magnitude and direction when speaking about units that are not obvious to us humans (like time)
Hadriscus@lemm.ee 3 months ago
Thanks, but damn… I don’t even understand your explanation. 😥 I work with vectors in Blender, so I have an intuitive understanding of them as per your first definition. But how are they less intuitive when talking about time? I don’t get how this meme is structured
Jerkface@lemmy.world 3 months ago
I’ll give it a shot.
We can use vector spaces for thinking about things that aren’t primarily concerned with space, like we are in Blender. Let’s imagine something practical, if a bit absurd. Pretend we have unlimited access to three kinds of dough. Each has flour, water, and yeast in different ratios. What we don’t have access to is the individual ingredients.
Suppose we want a fourth kind of dough which is a different ratio of the ingredients from the doughs we have. If the ratios of the ingredients of the three doughs we already have are unique, then we are in luck! We can make that dough we want by combining some amount of the three we have. I’m fact, we can make any kind of dough that is a combination of those three ingredients.
In linear algebra, this is called linear independence. This is actually an example of polynomial space that another user mentioned. Each dough is a vector, and each ingredient is a component. We have three equations (doughs) in three variables (ingredients).
This is a three dimensional vector space, which is easy to visualize. But there is no limit to how many dimensions you can have, or what they can represent. Some economic models use vectors with thousands of dimensions representing inputs and outputs of resources. Hopefully my explanation helps us see how vectors can sometimes be more difficult to imagine as directions and magnitudes.
kamenlady@lemmy.world 3 months ago
It isn’t structured using magnitude and direction.
Hadriscus@lemm.ee 3 months ago
Alright. This doesn’t help much either to be honest. It’s the same words as in the picture
kamenlady@lemmy.world 3 months ago
I just played with the words in the meme, because i don’t understand it either.
I should’ve put the /s
someacnt_@lemmy.world 3 months ago
It is just to consider polynomials and functions as vectors, and apply our meager intuition on 3d spaces. By introducing norms (size), you recover the “size and direction” analogy.
F04118F@feddit.nl 3 months ago
Check CompassRed’s comment above.
The definition part of the wikipedia article has a nice table with these “nice relationships for addition and scaling”. You will see that they also hold for many kinds of functions, such as polynomials and other more abstract things than points and directions in 2D or 3D. N-dimensional vectors for example, or using complex numbers, or both