It's std::vector that was weirdly named. In plenty of codebases "Vector", particularly gamedev and scientific, will mean the mathematical object with that name.
Other languages don't need to replicate this mistake.
Other languages don't need to replicate this mistake.
Zig: ArrayList
GLib: GArray
Objective-C: NSMutableArray
So List would have been the more Java/Zig way to name it (also Python, etc.)
You probably know that, but just to clarify: it's backed by a single array, reallocated repeatedly, just like std::vector in C++ (although growth factors are different, I think).
Just "List" probably risks that some people will jump to the conclusion that it's a linked list. I'd probably prefer the full "ArrayList". Although personally I'd use something like "DynArray"/"DynamicArray".
var kek: array of int;
setlength(kek, 666); // kek is now int[666]
setlength(kek, 1337); // kek is now int[1337]
1. std::vector doesn't have a fixed dimensionality, as would a mathematical vector. A fixed-length array actually makes more sense as a vector.
2. It doesn't provide the operations of addition and multiplication by scalars out-of-the-box (though you can whip up your own). Moreover, in general those operations wouldn't make sense for the elements which can be stored in a std::vector. E.g. neither multiplying bank account numbers by scalars, nor adding two bank account numbers make any sense. It would be good if you modelled them with types which don't allow those operations. Yet storing them in a std::vector makes perfect sense. But std::vector (or tuple) of bank account numbers is not a vector.
2. Operations are not intrinsic to a set, but to an algebra. Why would there need to be any correspondence between the operations of linear algebra and those of banking algebra in order to call an std::vector a vector?
Anyway, as another commenter pointed out, Stepanov himself, who gave this container its name, said that it has nothing to do with vectors, and he wouldn't name it vector, if he could correct this mistake.
> you can construct a vector space out of a set of non-vectors (such as matrices)
A vector is by definition no more and no less than an element of a vector space. Vectors are defined by vector spaces, not the other way around.
If you have a vector space whose elements are matrices, then those matrices are vectors. And they will be written in coefficients in a given base as tuples.
> out of operations other than vector addition and scalar multiplication
You don't "build vectors out of operations like vector addition and scalar multiplication", as in: you don't choose them. You choose the field and dimension, and those operations (vector addition and scalar multiplication) are a consequence.
> you can use vectors for purposes other than constructing vector spaces, also without involving either of those operations
Again, you don't construct vector spaces out of vectors - there are no vectors without vector spaces. And there are no vector spaces without those operations. But yes, you can use vectors from a given vector space in a greater capacity than just as vectors.
An example, which shows the futility of looking at vectors as just tuples: a real number is a vector in the vector space of real numbers over the field of rational numbers.
It's the definition I was given. If you accept that the word "vector" may be given a definition different from the one you give it, you'll need to concede that an std::vector may be a vector.
>you don't choose them. You choose the field and dimension, and those operations (vector addition and scalar multiplication) are a consequence.
You're using the phrase "vector addition and scalar multiplication" in a different sense than I meant. I was referring to component-wise addition between two vectors and to multiplication between a scalar and the individual components of a vector. You could choose different operations to construct a vector space, as long as they meet the requirements of vector spaces.
You used the phrase to refer to the constructing operations of a vector space. So yes, a vector space is indeed constructed out of the operations it is constructed out of. You could have been more charitable in your interpretation of my words, rather than assume I was saying something equivalent to "four-cornered triangle".
A vector is an element of a vector space, basically anything that you can add together and multiply with an element of a field. It has nothing to do with what you wrote above.
[] : https://en.wikipedia.org/wiki/Vector_(mathematics_and_physic...
Link to lecture by Stepanov: https://www.youtube.com/watch?v=etZgaSjzqlU
Furthermore in his book "From Mathematics to Generic Programming", Stepanov says that if he could change its name, he'd have named it "array".
No, because you can't prove that std::vector<T> obeys all vector space axioms[1] for all T, which is good because it's impossible, I can trivially define a T that will break any number of axioms and the cpp compiler will happily let me instantiate std::vector on it.
[1] https://www.math.ucla.edu/~tao/resource/general/121.1.00s/ve...
The Java Vector features will be out of incubator in the next year or so and unlike the existing Vector, it's actually useful. For context the new vector features are for SIMD support on the JVM.
I only know about it from dealing with J2ME crap where ArrayList wasn't available.