help-gnu-emacs
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: why are there [v e c t o r s] in Lisp?


From: Emanuel Berg
Subject: Re: why are there [v e c t o r s] in Lisp?
Date: Sat, 17 Oct 2015 23:37:23 +0200
User-agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4 (gnu/linux)

"Pascal J. Bourguignon" <pjb@informatimago.com>
writes:

> Nobody but you is confusing arrays with matrices,
> since they're not the same thing.
>
> vectors are arrays. matrices are arrays.
> tensors are arrays.

In the abstract sense, a list is a vector and a vector
is a matrix and a matrix is an array. And an array,
if 1-dimensional, is a list.

In the math world there are vectors and matrices (and
more :).

In the programming world there are lists and arrays
which can implement various math concepts including
vectors and matrices.

In many programming languages, 1-dimensional arrays
are called arrays as well as multidimensional arrays.
In Lisp, 1-dimensional arrays are called vectors.
Because of this, one might think they are to be used
specifically to do the vectors of linear algebra.
But this isn't so.

Conceptually everything is arrays, and everything is
matrices - only to reduce confusion it makes sense to
keep the terminology apart, with the exception of Lisp
1-dimenisonal arrays, which should be called vectors,
because that is what that are called and that word is
used when you use them in code. And they are vectors
as well, so there is not harm calling them that.

-- 
underground experts united
http://user.it.uu.se/~embe8573




reply via email to

[Prev in Thread] Current Thread [Next in Thread]