I have $n$ positive integers and let $R\subseteq \{1,\dots, n\}$ so that $|R|=r$.
I also have a $r \times r$ matrix called $T$.
I define a matrix that arises from the $n \times n$ identity matrix by replacing the $r$ rows and $r$ columns corresponding to the index set $R$, by $T$.
Say $$T=\begin{pmatrix} 2&3 \\ 4&5 \end{pmatrix} \quad n=4 \quad R=\{1,4\}$$ then my matrix is $$\begin{pmatrix} 2& 0& 0 &3 \\ 0& 1& 0& 0 \\ 0& 0& 1 &0 \\ 4 &0 &0& 5 \end{pmatrix}$$ Question : Does this matrix have a special name/notation?
Thank you.