Como alinhar verticalmente as três colunas do tampo, topo e meio da minha mesa

Question

Gostaria que as fórmulas da terceira coluna estivessem alinhadas verticalmente ao meio, ou seja, as fórmulas deveriam ficar verticalmente no meio das duas linhas das descrições.

\documentclass{article}
\usepackage{amsmath}
\usepackage{tabularx,booktabs}
\usepackage{caption}
\begin{document}
\begin{table}[htb]
    \centering
    \caption{I would like the formulae here to be vertically at the middle of the two lines of text}
    \begin{tabularx}{\linewidth}{lX>{$}c<{$}}
        \toprule
        Name & Description & \multicolumn{1}{c}{Formula}\\
        \midrule
        Ducks & Something which goes on two lines, something which goes on two lines &
        A=\dfrac{B}{C}\\
        Lions & Something which goes on two lines, something which goes on two lines &
        D=\dfrac{E}{F}\\
        \bottomrule
    \end{tabularx}
\end{table}
\begin{table}[htb]
    \centering
    \caption{Here the formulae are correctly aligned with the description, but I would like the name at the top like in the previous table}
    \begin{tabular}{lm{24em}>{$}c<{$}}
        \toprule
        Name & Description & \multicolumn{1}{c}{Formula}\\
        \midrule
        Ducks & Something which goes on two lines, something which goes on two lines &
        A=\dfrac{B}{C}\\
        Lions & Something which goes on two lines, something which goes on two lines &
        D=\dfrac{E}{F}\\
        \bottomrule
    \end{tabular}
\end{table}
\end{document}

Answer 1

Aqui está uma solução baseada na redefinição do Xtipo de coluna, e dois hacks possíveis para a primeira coluna (podem ter que ser adaptados ao conteúdo real):

\documentclass{article}
\usepackage{amsmath}
\usepackage{tabularx, booktabs, makecell}
\renewcommand{\tabularxcolumn}[1]{m{#1}}

\begin{document}

\begin{table}[htb]
    \centering
    \begin{tabularx}{\linewidth}{lX>{$}c<{$}}
        \toprule
        Name & Description & \multicolumn{1}{c}{Formula}\\
        \midrule
       \makecell[l]{Ducks\\\mbox{}} & Something which goes on two lines, something which goes on two lines &
        A=\dfrac{B}{C}\\
\addlinespace
        \makecell[l]{Lions\\\mbox{}} & Something which goes on two lines, something which goes on two lines &
        D=\dfrac{E}{F}\\
\addlinespace
       \raisebox{1.4ex}{Lions} & Something which goes on two lines, something which goes on two lines &
        D=\dfrac{E}{F}\\
        \bottomrule
    \end{tabularx}
\end{table}

\end{document} 

Answer 2

Isto é bastante difícil: o problema é que você deseja alinhar a caixa do meio de duas maneiras: à esquerda ao longo da linha de base, à direita ao longo do centro. Este tipo de tabela normalmente requer aninhamento de tabelas (o que é difícil com tabularx) ou medição de parte do conteúdo para usar truques do \llap.

Estamos faltando aqui o código tabular baseado em xcoffins que possui mais de um identificador ...

\documentclass{article}
\usepackage{amsmath}
\usepackage{tabularx,booktabs}
\usepackage{caption,xcoffins}
\newlength\colA

\begin{document}
\begin{table}[htb]
    \centering
    \renewcommand{\tabularxcolumn}[1]{m{#1}}
    \settowidth\colA{\begin{tabular}{l}Name\\Ducks\\Lions\end{tabular}}
    \caption{I would like the formulae here to be vertically at the middle of the two lines of text}
    \begin{tabularx}{\linewidth}{p{\dimexpr\colA-2\tabcolsep}X>{$}c<{$}}
        \toprule
        Name & Description & \multicolumn{1}{c}{Formula}\\
        \midrule
             &\leavevmode\llap{\makebox[\colA][l]{Ducks}}Something which goes on two lines, something which goes on two lines &
        A=\dfrac{B}{C}\\
             &\leavevmode\llap{\makebox[\colA][l]{Lions}}Something which goes on two lines, something which goes on two lines and on one more line and on one more line and on one more line &
        D=\dfrac{E}{F}\\
        \bottomrule
    \end{tabularx}
\end{table}

%Only for show some coffin code:

\NewCoffin\CoffinA
\NewCoffin\CoffinB
\NewCoffin\CoffinC

\SetHorizontalCoffin\CoffinA{Ducks}
\SetHorizontalCoffin\CoffinC{$D=\dfrac{E}{F}$}

\SetVerticalCoffin\CoffinB{\dimexpr \textwidth-\CoffinWidth\CoffinA-\CoffinWidth\CoffinC-6\tabcolsep}{\noindent Something which goes on two lines, something which goes on two lines and on one more line and on one more line and on one more line}

\JoinCoffins\CoffinA[H,r]\CoffinB[T,l](2\tabcolsep,0pt)
\JoinCoffins\CoffinA[vc,r]\CoffinC[vc,l](2\tabcolsep,0pt)
\noindent\hspace*{\tabcolsep}\TypesetCoffin\CoffinA
\end{document}

Answer 3

Assim:

Editar:

A posição do conteúdo das colunas é determinada pela linha de base da linha, que (infelizmente) não pode ser alterada de coluna para coluna.

Até agora não vejo outra possibilidade a não ser usar caixas na última ou na primeira coluna, que alinham sua linha de base. Um bom candidato para o seu caso específico é \adjustbox:

\documentclass{article}
\usepackage{amsmath}
\usepackage{tabularx,booktabs}
\usepackage{caption}

\usepackage{adjustbox}

\begin{document}
\begin{table}[htb]
    \centering
    \caption{I would like the formulae here to be vertically at the middle of the two lines of text}
    \begin{tabularx}{\linewidth}{lXc}
        \toprule
        Name & Description & Formula    \\
        \midrule
        Ducks & Something which goes on two lines, something which goes on two lines &
        \adjustbox{valign=t}{$A=\dfrac{B}{C}$}\\
        Lions & Something which goes on two lines, something which goes on two lines &
        \adjustbox{valign=t}{$D=\dfrac{E}{F}$}\\
        \bottomrule
    \end{tabularx}
\end{table}
\end{document}

Para uma escrita mais conveniente da tabela, você pode definir um novo tipo de coluna:

\newcolumntype{E}{>{\begin{adjustbox}{valign=t}$}c<{$\end{adjustbox}}}

e então escreva a tabela (corpo) como:

    \begin{tabularx}{\linewidth}{lXE}
        \toprule
        Name & Description & Formula    \\
        \midrule
        Ducks & Something which goes on two lines, something which goes on two lines &
        A=\dfrac{B}{C}\\
        Lions & Something which goes on two lines, something which goes on two lines &
        D=\dfrac{E}{F}\\
        \bottomrule
    \end{tabularx}

Se o texto nas células da coluna do meio tiver um número arbitrário de linhas, ou se a equação tiver apenas uma linha, o resultado será pior. Nesse caso, uma solução possível é usar multirowna primeira coluna e ajustar manualmente o número de colunas que essas células abrangem, e na segunda coluna definir a linha de base no meio vertical:

\documentclass{article}
\usepackage{amsmath}
\usepackage{booktabs, multirow, tabularx}
\usepackage{caption}

\usepackage{adjustbox}
\usepackage{lipsum}

\begin{document}
\begin{table}[htb]
    \centering
    \renewcommand\tabularxcolumn[1]{m{#1}} % <---
    \caption{I would like the formulae here to be vertically at the middle of the two lines of text}
    \begin{tabularx}{\linewidth}{lX>{$}c<{$}}
        \toprule
        Name & Description & Formula    \\
        \midrule
\multirow{-6}{*}{Ducks} % <--- manually adjusted
      & \lipsum[66] & A=\dfrac{B}{C}\\
        \bottomrule
    \end{tabularx}
\end{table}
\end{document}

ou use a solução proposta na resposta de @Bernard.

Answer 4

Para ter uma visão completa das possibilidades, incluo uma tabela composta com a ajuda dechamadas. É muito fácil ter esses alinhamentos usando um arquivo calstable. Removi os rolamentos dos lados esquerdo e direito, que adicionam código, não estritamente necessário para a criação da tabela do OP:

\documentclass{article}
\usepackage{cals, caption, amsmath}
\usepackage{lmodern}

\begin{document}

\begin{table*}
\caption{I would like the formulae here to be vertically at the middle of the two lines of text}
\begin{calstable}[c]
% Defining columns relative to each other and relative to the margins
\colwidths{{\dimexpr(\columnwidth)/6\relax}
            {\dimexpr(\columnwidth)/6*4\relax}
            {\dimexpr(\columnwidth)/6\relax}
            }

% Set up the tabular
\makeatletter
\def\cals@framers@width{0.8pt}   % Outside frame rules, reduce if the rule is too heavy
\def\cals@bodyrs@width{0.6pt}
\def\cals@cs@width{0pt}             % Inside rules, reduce if the rule is too heavy
\def\cals@rs@width{0.4pt}

\def\bb{\ifx\cals@borderB\relax     % Botton border switch (off-on)
    \def\cals@borderB{0pt}
\else \let\cals@borderB\relax\fi}

\def\lp{\ifdim\cals@paddingL=0.0pt\relax    % Left padding switch (off-on)
    \cals@setpadding{Ag}
\else \setlength{\cals@paddingL}{0pt}\fi}

\def\rp{\ifdim\cals@paddingR=0.0pt\relax    % Right padding switch (off-on)
    \cals@setpadding{Ag}
\else \setlength{\cals@paddingR}{0pt}\fi}


% R1H1
\thead{\small%
\brow
    \lp\alignL\cell{Name}\lp
    \alignL\cell{Description}
    \rp\alignR\cell{Formula}\rp
\erow
\normalsize%
}
\tfoot{\lastrule\strut}
%R2B1
\brow
    \lp\bb\alignL\cell{Ducks}\lp
    \alignL\cell{Something which goes on two lines, something which goes on two lines}
    \rp\alignR\cell{\vfil$A=\dfrac{B}{C}$}\rp
\erow
%R3B2
\brow
    \bb\lp\alignL\cell{Gnus}\lp
    \alignL\cell{Something which goes on two lines, something which goes on two lines and on one more line and on one more line and on one more line}
    \rp\alignR\cell{\vfil$D=\dfrac{E}{F}$}\rp\bb
\erow
%R4B3
\brow
    \lp\alignL\cell{Gnats}\lp
    \alignL\cell{Something which goes on two lines, something which goes on two lines and on one more line and on one more line and on one more line}
    \rp\alignR\cell{\vfil $D=\dfrac{E}{F}$}\rp
\erow
\makeatletter
\end{calstable}\par
\end{table*}
\end{document}