等式中的空格

Question

&我正在写一篇论文，我想在我的 latex 文档中复制这组方程。但是当我尝试多次进行对齐时，我得到了错误。

\begin{eqnarray}
    \label{Eq:GeosWind}
    \frac{\partial u}{\partial t} &+& \overrightarrow{v}\nabla u + \frac{1}{\rho}\frac{\partial p}{\partial x}  -fv +f^{\ast}w \mp v \frac{\vert\overrightarrow{v}\vert}{r}  + F_x = 0 \label{a}\\
    \frac{\partial v}{\partial t} + \overrightarrow{v}\nabla u + \frac{1}{\rho}\frac{\partial p}{\partial y} + fu \pm u \frac{\vert\overrightarrow{v}\vert}{r} +F_y = 0 \label{b}\\
    \frac{\partial w}{\partial t} + \overrightarrow{v}\nabla w + \frac{1}{\rho}\frac{\partial p}{\partial y} -g -f^{\ast}u  + F_z = 0 \label{c}\\
    I &&   II    III   IV    V    VI   VII
\end{eqnarray}

Answer 1

这是一个包含alignat(7columns) 和的解决方案eqparbox。我还加载了esdiff和esvect包，以便更简单地输入偏微分，并获得更漂亮的箭头提示：

\documentclass{article}
\usepackage[b]{esvect}
\usepackage{esdiff}
\usepackage{eqparbox}
\newcommand{\eqmathbox}[2][M] {\eqmakebox[#1]{$\displaystyle#2$}}
\usepackage{amsmath}

\begin{document}

    \begin{alignat}{7}
 \diffp{u}{t} &+{} &\vv{v}\nabla u & +{} & \frac{1}{\rho}\diffp{p}{x} & & & -{} & fv & +{} & f^{\ast}w & \mp{} & v \frac{\vert\vv{v}\vert}{r}& + F_x = 0 \label{a}\\
 \diffp{v}{t} &+{} & \vv{v}\nabla u & + {} & \frac{1}{\rho}\diffp{p}{ y} & & & +{} & fu & & & \pm{} &\eqmathbox[VI]{u\frac{\vert\vv{v}\vert}{r}} & +F_y = 0 \label{b}\\
   \eqmathbox[I]{\diffp{w}{t}} &+{} &\eqmathbox[II] {\vv{v}\nabla w } & +{} & \eqmathbox[III]{\frac{1}{\rho}\diffp{p}{y}} &-{} & \eqmathbox[IV]{g} & -{} & \eqmathbox[V]{f^{\ast}u} & & & & & + F_z = 0\label{c} \\
   \eqmakebox[I]{I} & & \eqmakebox[II]{II}& & \eqmakebox[III]{III} & & \eqmakebox[IV]{IV}& & \eqmakebox[V]{V} & & & & \eqmakebox[VI]{VI} & \phantom{ + }\text{VII} \notag
    \end{alignat}%

\end{document}