如何右对齐矩阵

Question

\begin{align*}
 \mathbf{J}_{f}
 = \begin{bmatrix}
   -2 x \sin\left(y\right) ^{2} & -2x^{2}\sin\left(y\right) \cos\left(y\right) &  0
   \\
   \sin\left(y\right)  & x \cos\left(y\right)  & 0
   \\
   2x & 0 & 0
 \end{bmatrix} 
.\end{align*}

我如何右对齐矩阵，以便例如与第一列对齐sin(y)而-2不是在中间。

Answer 1

您可以使用mathtools提供的bmatrix*

\documentclass{article}
\usepackage{mathtools} % also loads amsmath

\begin{document}

You can get left alignment
\begin{equation*}
\mathbf{J}_{f} =
\begin{bmatrix*}[l]
  -2 x \sin(y) ^{2} & -2x^{2}\sin(y) \cos(y) &  0
  \\
  \sin(y)  & x \cos(y)  & 0
  \\
  2x & 0 & 0
\end{bmatrix*}.
\end{equation*}
or, alternatively, right alignment
\begin{equation*}
\mathbf{J}_{f} =
\begin{bmatrix*}[r]
  -2 x \sin(y) ^{2} & -2x^{2}\sin(y) \cos(y) &  0
  \\
  \sin(y)  & x \cos(y)  & 0
  \\
  2x & 0 & 0
\end{bmatrix*}.
\end{equation*}
but I find neither to be prettier than with the standard
center alignment
\begin{equation*}
\mathbf{J}_{f} =
\begin{bmatrix}
  -2 x \sin(y) ^{2} & -2x^{2}\sin(y) \cos(y) &  0
  \\
  \sin(y)  & x \cos(y)  & 0
  \\
  2x & 0 & 0
\end{bmatrix}.
\end{equation*}

\end{document}

一些不相​​关的评论。在这种情况下避免使用\left和\right：它们只会增加不必要的间距。还align应该用于对齐几个方程。

Answer 2

array使用环境（甚至没有）就可以获得右对齐amsmath。

\documentclass{article}
\begin{document}
Right alignment can be obtained using \verb|array| environment.
\begin{equation}
\mathbf{J}_{f} =\left[
\begin{array}{rrr}
-2 x \sin(y) ^{2}&-2x^{2}\sin(y) \cos(y) &  0   \\
\sin(y)  & x \cos(y)  & 0   \\
2x & 0 & 0
\end{array}\right].
\end{equation}
\end{document}

Answer 3

旧软件包还spalign提供了右/中/左对齐矩阵。事实上，您可以看到可以获得与其他用户相同的输出。

\documentclass[a4paper,12pt]{article}
\usepackage{amsmath,amssymb}
\usepackage{spalign}
\usepackage{parskip}


\begin{document}
Center option
\[\mathbf{J}_{f}=\spaligndelims{[}{]}
\spalignmat[c]{-2x\sin(y)^{2} -2x^{2}\sin(y)\cos(y)  0; \sin(y) x\cos(y) 0; 2x 0 0} 
.\]
Left option 
\[\mathbf{J}_{f}=\spaligndelims{[}{]}
\spalignmat[l]{-2x\sin(y)^{2} -2x^{2}\sin(y)\cos(y)  0; \sin(y) x\cos(y) 0; 2x 0 0} 
.\]
Right option
\[\mathbf{J}_{f}=\spaligndelims{[}{]}
\spalignmat[r]{-2x\sin(y)^{2} -2x^{2}\sin(y)\cos(y)  0; \sin(y) x\cos(y) 0; 2x 0 0} 
.\]
\end{document}

Answer 4

环境{bNiceMatrix}具有nicematrix（除其他功能外）用于水平对齐的键r和。l

\documentclass{article}
\usepackage{nicematrix}

\begin{document}

You can get left alignment
\begin{equation*}
\mathbf{J}_{f} =
\begin{bNiceMatrix}[l]
  -2 x \sin(y) ^{2} & -2x^{2}\sin(y) \cos(y) &  0
  \\
  \sin(y)  & x \cos(y)  & 0
  \\
  2x & 0 & 0
\end{bNiceMatrix}.
\end{equation*}
or, alternatively, right alignment
\begin{equation*}
\mathbf{J}_{f} =
\begin{bNiceMatrix}[r]
  -2 x \sin(y) ^{2} & -2x^{2}\sin(y) \cos(y) &  0
  \\
  \sin(y)  & x \cos(y)  & 0
  \\
  2x & 0 & 0
\end{bNiceMatrix}.
\end{equation*}

\end{document}