# Horizontal line in Matrix

This question is building from the post found here. How to move the horizontal dashed line so that it is slightly further away from the superscript "T"? Also, when this horizontal line is moved, how to then horizontally align all the three horizontal dashed lines? Here is the solution code found from the original link:

\documentclass{article}
\usepackage{amsmath}
\usepackage{arydshln}

\begin{document}

$$\left[ \begin{array}{c;{2pt/2pt}c} N & B_i \\ \hdashline[2pt/2pt] B_i^T & 0 \end{array} \right] \left[ \begin{array}{c} x_i \\ \hdashline[2pt/2pt] k \end{array} \right] =\left[ \begin{array}{c} n \\ \hdashline[2pt/2pt] 0 \end{array} \right] \text{ with } n = A^TPl$$

\end{document}


Change \arraystretch:

\renewcommand{\arraystretch}{1.4}   %% adjsut as you wish


Code:

\documentclass{article}
\usepackage{amsmath}
\usepackage{arydshln}

\begin{document}

$$\renewcommand{\arraystretch}{1.4} \left[ \begin{array}{c;{2pt/2pt}c} N & B_i \\ \hdashline[2pt/2pt] B_i^T & 0 \end{array} \right] \left[ \begin{array}{c} x_i \\ \hdashline[2pt/2pt] k \end{array} \right] =\left[ \begin{array}{c} n \\ \hdashline[2pt/2pt] 0 \end{array} \right] \text{ with } n = A^TPl$$

\end{document}


You can also define a \strut of your own

\newcommand{\mystrut}{\rule{0pt}{2.5ex}}

and use it like

\documentclass{article}
\usepackage{amsmath}
\usepackage{arydshln}
\newcommand{\mystrut}{\rule{0pt}{2.5ex}}

\begin{document}

$$%\renewcommand{\arraystretch}{1.4} \left[ \begin{array}{c;{2pt/2pt}c} N & B_i \\ \hdashline[2pt/2pt] \mystrut B_i^T & 0 \end{array} \right] \left[ \begin{array}{c} x_i \\ \hdashline[2pt/2pt] \mystrut k \end{array} \right] =\left[ \begin{array}{c} n \\ \hdashline[2pt/2pt] \mystrut 0 \end{array} \right] \text{ with } n = A^TPl$$

\end{document}