Is there any notation indicating a subvector of a matrix ? I need to know the correct way of showing it in an academic paper.
i.e:
Let
$$
A=\begin{bmatrix}
2& -10 & 0 & 4\\
5& 11 & 8 & -5\\
-9& 3 & -3 & 19
\end{bmatrix}
$$
What's the notation of a vector indicates the first row of matrix A:
$$
??=\begin{bmatrix}
2& -10 & 0 & 4\\
\end{bmatrix}
$$
And also the notation of a vector indicates the first column of matrix A:
$$
??=\begin{bmatrix}
2&\\
5&\\
-9&
\end{bmatrix}
$$
Best Answer
Uhm.. In such a case you can just write as following.
Let's say that you want to write down the $i-$ row and the $j-$ column of matrix $A$. Then you can write:
$e_i^T \cdot A,$ where $e_i^T$ is the $i-$ row of the identity matrix.
$A\cdot e_j$, where $e_j$ is the $j-$ column of the identity matrix.