Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

Suppose you have a matrix $A$. Is there a "standard"/mathematical elegant way to denote all members of the matrix as a set?

So suppose there is a matrix $A = \left[ \begin{array}{cc} a & b \\ c & d \end{array} \right] $ then I would like to define $set(A) = \{ a,b,c,d \}$

share|improve this question
1  
If you define your own notation and it becomes popular, everybody will speak about the dtech-notation for matrix-elements! ;p –  Raskolnikov Mar 29 '11 at 15:48
7  
We call them the "entries of $A$", and usually refer to them that way. So you would write $\{x\mid x\text{ is an entry of }A\}$. –  Arturo Magidin Mar 29 '11 at 15:49
2  
$\cup_{ij}\{A_{ij}\}$, maybe. –  mjqxxxx Mar 29 '11 at 15:58
1  
There are some problems with this notation: in fact, something like $\{ a,b,c,d\}$ does not have "memory" of the place of each entry in the matrix (hence $A=\begin{pmatrix} a & b\\ c & d\end{pmatrix}$ and $B=\begin{pmatrix} a & c\\ d & b\end{pmatrix}$ have $set(A)=set(B)$ even if $A\neq B$), nor of the quantity of each entry in the matrix (therefore $I=\begin{pmatrix} 1 & 0\\ 0 & 1\end{pmatrix}$ and $M=\begin{pmatrix} 1 & 1\\ 1 & 0\end{pmatrix}$ have $set (I)= set (M)$ even if $I\neq M$)... –  Pacciu Mar 29 '11 at 16:09
2  
@Arturo Ok, $set(A)=\{x\;|\;x\,is\,an\,entry\,of\,A\}$ seem nice enough @Pacciu That is not a problem, that is just a consequence of transforming the matrix to a set. Clearly $set^{inv}$ can't exist and $set(A)$ might equal $set(B)$ even if $A \neq B$ but neither is required. –  dtech Mar 29 '11 at 16:18
show 4 more comments

Know someone who can answer? Share a link to this question via email, Google+, Twitter, or Facebook.

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.