mathematical symbol for vector appending

Question

Given a vector $v=<1,2,3>$ I want to have a new vector $v'$, which is the vector $v$, appends with a number $4$. How should I represent $v'$ mathematically?

What I wish to have is something like $v'=v^4=<1,2,3,4>$, where ^ is an appending symbol for vector (therefore my main question is, does it exist such "vector appending" symbol in maths?)

This question has also been asked at tex.SE: http://tex.stackexchange.com/questions/8397 — Douglas S. Stones, Nov 15 '12 at 03:02
We rarely append vectors. We do append other things (like words, although we use the fancier verb «to yuxtapose») and then we use no sign, just like multiplication. — Mariano Suárez-Álvarez, Feb 01 '15 at 03:39

score 3 · Answer 1 · answered May 19 '15 at 13:49

A fairly common notation for the concatenation of two sequences is $s^\frown t$. In the special case where $t$ consists of a single element $a$ you'd have $s^\frown\langle a\rangle$. The TeX code for the symbol $\frown$ is \frown, and to raise it to the desired level you'd make it a superscript.

score 1 · Answer 2 · answered Feb 01 '15 at 03:10

1

I usually see it being represented by writing $v=\left[1, 2, 3\right]$, $w=\left[4\right]$, and then $$\left[v,w\right]=\left[v,4\right]=\left[1,2,3,4\right]$$

This is similar to MATLAB notation, so it might be more common in computing-related contexts.

answered Feb 01 '15 at 03:10

fonini

2,728

4

This is a natural application of block matrix notation. If we can write $$\begin{bmatrix}\mathbf A&\mathbf b\\mathbf b^T&c\end{bmatrix}$$ where $\mathbf A$, $\mathbf b$, and $c$ are a matrix, a column vector, and a scalar respectively, then surely we can write $$\begin{bmatrix}\mathbf v\w\end{bmatrix}$$ to denote $$\begin{bmatrix}v_1\v_2\\vdots\v_n\w\end{bmatrix}$$ (and we do). – May 19 '15 at 14:40

mathematical symbol for vector appending

2 Answers2