Math & Science ⇒ Help with aligning

[xerion]

Seems like I need the precious help of the community again !
I did my best to bring it close to a form that i would like but there are probably better ways to do it. I am open to any suggestions !

So I have this matrix that is shown in the code below which is fine if i can get the vertical line of the last submatrix to align with the bracket. Trying to do so gives me a lot of trouble with \right. stuff which i can not sort out.

Any ideas ?

Code: Select all

\documentclass{article}

\usepackage{amssymb}
\usepackage{amsmath}

\makeatletter
\renewcommand*\env@matrix[1][*\c@MaxMatrixCols c]{%
  \hskip -\arraycolsep
  \let\@ifnextchar\new@ifnextchar
  \array{#1}}
\makeatother


\begin{document}
\setcounter{MaxMatrixCols}{12}

\begin{equation*}
	\begin{split}
		A =& 
		\begin{bmatrix}[c|c|c]
			A_1 & A_2 & A_3 
		\end{bmatrix}
		\\ =& \left[
		\begin{matrix}[cccc|]
			\frac{\partial f_x}{\partial a} & \frac{\partial f_x}{\partial b} & \frac{\partial f_x}{\partial c} & \frac{\partial f_x}{\partial d} \\
			\frac{\partial f_y}{\partial a} & \frac{\partial f_y}{\partial b} & \frac{\partial f_y}{\partial c} & \frac{\partial f_y}{\partial d}
		\end{matrix} \right. \quad \cdots
		\\ & \left.
		\begin{matrix}[|cccccccc|ccc]
			-A & -B & -C & -D & 0 & 0 & 0 & 0 & -A_1 & -A_2 & -A_3 \\
			0 & 0 & 0 & 0 & -A & -B & -C & -D & -A_1 & -A_2 & -A_3
		\end{matrix} \right]
	\end{split}
\end{equation*}

\end{document}

[localghost]

An invisible equal sign with some negative space should do the trick.

Code: Select all

\documentclass{article}
\usepackage{amssymb}
\usepackage{amsmath}

\makeatletter
\renewcommand*\env@matrix[1][*\c@MaxMatrixCols c]{%
  \hskip -\arraycolsep
  \let\@ifnextchar\new@ifnextchar
  \array{#1}}
\makeatother


\begin{document}
  \setcounter{MaxMatrixCols}{12}

  \begin{equation*}
    \begin{split}
      A =&
      \begin{bmatrix}[c|c|c]
         A_1 & A_2 & A_3
      \end{bmatrix}
      \\ =& \left[
      \begin{matrix}[cccc|]
         \frac{\partial f_x}{\partial a} & \frac{\partial f_x}{\partial b} & \frac{\partial f_x}{\partial c} & \frac{\partial f_x}{\partial d} \\
         \frac{\partial f_y}{\partial a} & \frac{\partial f_y}{\partial b} & \frac{\partial f_y}{\partial c} & \frac{\partial f_y}{\partial d}
      \end{matrix} \right. \quad \cdots
      \\ & \phantom{=}\!\left.
      \begin{matrix}[|cccccccc|ccc]
         -A & -B & -C & -D & 0 & 0 & 0 & 0 & -A_1 & -A_2 & -A_3 \\
         0 & 0 & 0 & 0 & -A & -B & -C & -D & -A_1 & -A_2 & -A_3
      \end{matrix} \right]
    \end{split}
  \end{equation*}
\end{document}

Thorsten

[xerion]

Thank you for your help, much appreciated !
Sorry for replying this late but was quite busy ! Seems that I am not able to actually mark the topic as solved.