# How do you make the brackets of a row matrix the same boldness or thickness of a standard MxN matrix?

I have the following code:

\begin{align*}
\begin{cases}
\dot{\mathbf{x}} =
\begin{bmatrix*}
\phantom{-}3 & -4 & \phantom{-}2\phantom{-} \\
-2 & \phantom{-}0 & \phantom{-}1\phantom{-} \\
\phantom{-}4 & \phantom{-}7 & -5\phantom{-} \\
\end{bmatrix*}
\mathbf{x} +
\begin{bmatrix*}
\phantom{-}1\phantom{-} \\
-2\phantom{-} \\
-3\phantom{-} \\
\end{bmatrix*}
u(t), & \textbf{x}(0) = \begin{bmatrix*}
\phantom{-}0\phantom{-} \\ \phantom{-}0\phantom{-} \\ \phantom{-}0\phantom{-}
\end{bmatrix*} \\
\\ y = \begin{bmatrix*}
\phantom{-}1 & \phantom{-}7 & \phantom{-}1\phantom{-} \\
\end{bmatrix*}
\end{cases}
\end{align*}


Ignore the messy code and the random \phantom commands, that is just so I can have even and centered entries in each matrix. My problem is that the singular row matrix produces brackets that are more grey than the brackets of the matrices with more than one row. Is there a way to make it so that the all matrix brackets have the same boldness or thickness? I am willing to tip and reward someone who can solve my problem with the conditions that it work with the standard Overleaf font, as well as it being compatible with the cases environment. The same problem also arises regardless of which matrix limiter is used. The contents inside the matrix should not be distorted as well. ChatGPT is not able to solve this problem.

• Welcome to TeX.SE. Please post full MWE, i.e., from \documentclass to \end{document} Commented Sep 13, 2023 at 6:17

Rather than bother fiddling with the widths of the not-so-tall square brackets, I'd look to achieve a better overall placement of the elements in the material at hand. Since you're not making much use of the cases machinery, I'd ditch it in favor of a simpler \left\{ ... \right. framework, and I'd employ an aligned environment for the material to the right of the tall curly brace. Next, since there's nothing to align in the align* environment [pun intended], I'd replace it with an unpretentious equation* environment. Please don't mix and mismatch \mathbf{x} and \textbf{x} particles. Finally, if you feel strongly about the issue, you could insert \kern0.125em between y &= and \begin{bmatrix} in order to align the opening square brackets across the two rows of the aligned environment. With all these changes in place, readers will likely barely take note that the square brackets don't all have the same thickness.

Observe that the following code contains no \hphantom{-} particles.

\documentclass{article}
\usepackage{mathtools} % for 'bmatrix*' env.

\begin{document}

\begin{equation*}
\left\{
\begin{aligned}
\dot{\mathbf{x}} &=
\begin{bmatrix*}[r]
3 & -4 &  2 \\
-2 &  0 &  1 \\
4 &  7 & -5
\end{bmatrix*}
\mathbf{x} +
\begin{bmatrix*}[r]
1 \\
-2 \\
-3
\end{bmatrix*}
u(t),
\mathbf{x}(0) =
\begin{bmatrix}
0 \\ 0 \\ 0
\end{bmatrix} \\[\jot] % end of first row
y &=
\kern0.125em\begin{bmatrix}
1 & 7 & 1
\end{bmatrix}
\end{aligned}
\right.
\end{equation*}

\end{document}

• What if I am the only one bothered by the bracket size of the row matrix? Also, what is your Venmo/Paypal? Commented Sep 14, 2023 at 3:32
• @mrwillparker - If the premise of your first question holds, I'd say that you're doing just great. For if the purpose of your writing is to convince others of some argument, and if your readers do not think that some expression of yours might be an issue, then you must be succeeding in making your (main) argument. By implication, the expression you're concerned about cannot be an obstacle that's keeping you from making your argument clearly and convincingly. Oh, and I don't have Venmo or Paypal.
– Mico
Commented Sep 14, 2023 at 5:33