Como posso evitar a nova linha ao ajustar largura e eqnarray?

Question

adjustwidthinsere uma nova linha redundante somente quando é usada com eqnarray. Como posso evitar isso?

Entrada:

\documentclass{article}
\usepackage{changepage}

\begin{document}

\noindent
Hello World!
\begin{adjustwidth}{-1cm}{-1cm}
Hello World!
\end{adjustwidth}

\ \\
Hello World!
\begin{eqnarray}
f(x) = 1
\end{eqnarray}

\ \\
Hello World!
\begin{adjustwidth}{-1cm}{-1cm}
\begin{eqnarray}
f(x) = 1
\end{eqnarray}
\end{adjustwidth}

\end{document}

Saída:

Saída com legenda:

Tanto quanto eu meço com uma régua, a altura do espaço é duplicada quando com adjustwidth.

---

Entrada MWE:

\documentclass{article}
\usepackage[top=30truemm,bottom=30truemm,left=25truemm,right=25truemm]{geometry}

\usepackage{changepage}
\usepackage{braket}
\usepackage{bm}

\newcommand{\bmk}{{\bm{k}}}
\newcommand{\brac}[1]{\left( #1 \right)}
\newcommand{\expo}[1]{e^{#1}}
\newcommand{\ao}[1]{a_{#1}}
\newcommand{\aod}[1]{a^\dagger _{#1}}

\begin{document}

Operator $A$ is defined as
\begin{eqnarray}
A &=& \sum _{\bmk _1, \bmk _2} \Braket{\bmk _1, \uparrow | \hat{A} | \bmk _2, \uparrow} \left\{ \brac{\cos \theta _{\bmk _1} \cos \theta _{\bmk _2} - \eta \sin \theta _{\bmk _1} \sin \theta _{\bmk _2}} \brac{\aod{\bmk _1, \uparrow} \ao{\bmk _2, \uparrow} + \eta \aod{- \bmk _2, \downarrow} \ao{- \bmk _1, \downarrow}} \right. \nonumber \\
&\ & \hspace{3cm} \left. + \brac{\cos \theta _{\bmk _1} \sin \theta _{\bmk _2} + \eta \sin \theta _{\bmk _1} \cos \theta _{\bmk _2}} \brac{\aod{\bmk _1, \uparrow} \aod{- \bmk _2, \downarrow} + \eta \ao{- \bmk _1, \downarrow} \ao{\bmk _2, \uparrow}} \right\}.
\end{eqnarray}

The Heisenberg representation of this gives 
\begin{eqnarray}
A(t) &=& \sum _{\bmk _1, \bmk _2} \Braket{\bmk _1, \uparrow | \hat{A} | \bmk _2, \uparrow} \left\{ \brac{\cos \theta _{\bmk _1} \cos \theta _{\bmk _2} - \eta \sin \theta _{\bmk _1} \sin \theta _{\bmk _2}} \brac{\aod{\bmk _1, \uparrow} \ao{\bmk _2, \uparrow} \expo{\frac{i}{\hbar} (E_{\bmk _1} - E_{\bmk _2}) t} + \eta \aod{- \bmk _2, \downarrow} \ao{- \bmk _1, \downarrow} \expo{- \frac{i}{\hbar} (E_{\bmk _1} - E_{\bmk _2}) t}} \right. \nonumber \\
&\ & \hspace{1.5cm} \left. + \brac{\cos \theta _{\bmk _1} \sin \theta _{\bmk _2} + \eta \sin \theta _{\bmk _1} \cos \theta _{\bmk _2}} \brac{\aod{\bmk _1, \uparrow} \aod{- \bmk _2, \downarrow} \expo{\frac{i}{\hbar} (E_{\bmk _1} + E_{\bmk _2}) t} + \eta \ao{- \bmk _1, \downarrow} \ao{\bmk _2, \uparrow} \expo{- \frac{i}{\hbar} (E_{\bmk _1} + E_{\bmk _2}) t} } \right\}.
\end{eqnarray}

The Heisenberg representation of this gives 
\begin{adjustwidth}{-1cm}{-1cm}
\begin{eqnarray}
A(t) &=& \sum _{\bmk _1, \bmk _2} \Braket{\bmk _1, \uparrow | \hat{A} | \bmk _2, \uparrow} \left\{ \brac{\cos \theta _{\bmk _1} \cos \theta _{\bmk _2} - \eta \sin \theta _{\bmk _1} \sin \theta _{\bmk _2}} \brac{\aod{\bmk _1, \uparrow} \ao{\bmk _2, \uparrow} \expo{\frac{i}{\hbar} (E_{\bmk _1} - E_{\bmk _2}) t} + \eta \aod{- \bmk _2, \downarrow} \ao{- \bmk _1, \downarrow} \expo{- \frac{i}{\hbar} (E_{\bmk _1} - E_{\bmk _2}) t}} \right. \nonumber \\
&\ & \hspace{1.5cm} \left. + \brac{\cos \theta _{\bmk _1} \sin \theta _{\bmk _2} + \eta \sin \theta _{\bmk _1} \cos \theta _{\bmk _2}} \brac{\aod{\bmk _1, \uparrow} \aod{- \bmk _2, \downarrow} \expo{\frac{i}{\hbar} (E_{\bmk _1} + E_{\bmk _2}) t} + \eta \ao{- \bmk _1, \downarrow} \ao{\bmk _2, \uparrow} \expo{- \frac{i}{\hbar} (E_{\bmk _1} + E_{\bmk _2}) t} } \right\}.
\end{eqnarray}
\end{adjustwidth}

\end{document}

Saída MWE:

A Eq(2) é escrita sem adjustwidth. Isso é o suficiente quando vejo o pdf no meu computador, mas a parte da borda direita desaparece quando impresso. A Eq (3) é escrita com adjustwidth. É legível e imprimível. No entanto, há um espaço redundante inserido. (Na Eq(2) ou Eq(3), uma única equação é dividida em duas linhas. Não quero mais dividir a equação (em três ou mais linhas).)

Answer 1

Eu sugiro split. Nunca use eqnarraycom LaTeX, prefira os ambientes de alinhamento oferecidos pelo amsmath.

\documentclass{article}
\usepackage[top=30truemm,bottom=30truemm,left=25truemm,right=25truemm]{geometry}

\usepackage{amsmath}
\usepackage{changepage}
\usepackage{braket}
\usepackage{bm}

\newcommand{\bmk}{\bm{k}}
\newcommand{\brac}[1]{\left( #1 \right)}
\newcommand{\expo}[1]{e^{#1}}
\newcommand{\ao}[1]{a_{#1}}
\newcommand{\aod}[1]{a^\dagger_{#1}}
\newcommand{\up}{{\uparrow}}
\newcommand{\down}{{\downarrow}}

\begin{document}

Operator $A$ is defined as
\begin{equation}
\begin{split}
A = 
\sum_{\bmk_1, \bmk_2} \braket{\bmk_1, \up | \hat{A} | \bmk_2, \up} \bigl\{
& 
  (\cos\theta_{\bmk_1} \cos\theta_{\bmk_2} - \eta \sin\theta_{\bmk_1} \sin\theta_{\bmk_2})
  (\aod{\bmk_1, \up} \ao{\bmk_2, \up} + \eta \aod{- \bmk_2, \down} \ao{- \bmk_1, \down}) \\
{}+{} &
  (\cos\theta_{\bmk_1} \sin\theta_{\bmk_2} + \eta \sin\theta_{\bmk_1} \cos\theta_{\bmk_2})
  (\aod{\bmk_1, \up} \aod{- \bmk_2, \down} + \eta \ao{- \bmk_1, \down} \ao{\bmk_2, \up})
  \bigr\}.
\end{split}
\end{equation}
The Heisenberg representation of this gives 
\begin{equation}
\begin{split}
A(t) = \sum_{\bmk_1, \bmk_2} &\braket{\bmk_1, \up | \hat{A} | \bmk_2, \up}
\\
{}\cdot\bigl\{&
  (\cos\theta_{\bmk_1} \cos\theta_{\bmk_2} - \eta \sin\theta_{\bmk_1} \sin\theta_{\bmk_2})
  (\aod{\bmk_1, \up} \ao{\bmk_2, \up} \expo{\frac{i}{\hbar} (E_{\bmk_1} - 
    E_{\bmk_2}) t} + \eta \aod{- \bmk_2, \down} \ao{- \bmk_1, \down} 
    \expo{- \frac{i}{\hbar} (E_{\bmk_1} - E_{\bmk_2}) t})
\\
{}+{}&
  (\cos\theta_{\bmk_1} \sin\theta_{\bmk_2} + \eta \sin\theta_{\bmk_1} \cos\theta_{\bmk_2})
  (\aod{\bmk_1, \up} \aod{- \bmk_2, \down} \expo{\frac{i}{\hbar} (E_{\bmk_1} + E_{\bmk_2}) t} +
     \eta \ao{- \bmk_1, \down} \ao{\bmk_2, \up} 
     \expo{- \frac{i}{\hbar} (E_{\bmk_1} + E_{\bmk_2}) t}) \bigl\}.
\end{split}
\end{equation}

\end{document}

Algumas notas: Removi todos \leftos \rightcomandos, que dão cercas muito grandes ao redor. Também defini \upe \down, porque \uparrowe \downarrowsão símbolos de relação e podem produzir espaçamento ruim se usados ​​como símbolos comuns. Os colchetes na definição formam \upe \downse comportam como símbolos comuns em todos os lugares.

Answer 2

Primeiro, não use eqnarray– use alignem vez disso. Segundo, não há necessidade de recorrer à adjustwidthmarreta se você inserir algumas quebras de linha adicionais. Para maior legibilidade, considere usar \expa notação -dentro da \expomacro, como é feito na captura de tela a seguir.

\documentclass{article}
\usepackage[vmargin=3cm,hmargin=2.5cm]{geometry}
\usepackage{amsmath}
\allowdisplaybreaks
\usepackage{changepage}
\usepackage{braket}
\usepackage{bm}

\newcommand{\bmk}{{\bm{k}}}
\newcommand{\brac}[1]{\Bigl( #1 \Bigr)}
\newcommand{\expo}[1]{\exp\bigl(#1\bigr)}
\newcommand{\ao}[1]{a^{\vphantom{\dagger}}_{#1}}
\newcommand{\aod}[1]{a^\dagger _{#1}}

\begin{document}

Operator $A$ is defined as
\begin{align}
A &= \sum _{\bmk _1, \bmk _2} 
\Braket{\bmk _1, \uparrow | \hat{A} | \bmk _2, \uparrow}
\Bigl\{ 
  \brac{\cos \theta _{\bmk _1} \cos \theta _{\bmk _2} 
  - \eta \sin \theta _{\bmk _1} \sin \theta _{\bmk _2}} \notag\\
&\qquad\times\brac{\aod{\bmk _1, \uparrow} \ao{\bmk _2, \uparrow} 
  + \eta \aod{- \bmk _2, \downarrow} \ao{- \bmk _1, \downarrow}} \nonumber \\
&\quad+ \brac{\cos \theta _{\bmk _1} \sin \theta _{\bmk _2} 
  + \eta \sin \theta _{\bmk _1} \cos \theta _{\bmk _2}} 
  \brac{\aod{\bmk _1, \uparrow} \aod{- \bmk _2, \downarrow} 
  + \eta \ao{- \bmk _1, \downarrow} \ao{\bmk _2, \uparrow}}
\Bigr\}.\\
\intertext{The Heisenberg representation of this gives}
A(t) &= \sum _{\bmk _1, \bmk _2}
\Braket{\bmk _1, \uparrow | \hat{A} | \bmk _2, \uparrow}
\Bigl\{
  \brac{\cos \theta _{\bmk _1} \cos \theta _{\bmk _2} 
  - \eta \sin \theta _{\bmk _1} \sin \theta _{\bmk _2}} \notag\\
&\qquad\times\brac{\aod{\bmk _1, \uparrow} \ao{\bmk _2, \uparrow} 
  \expo{\tfrac{i}{\hbar} (E_{\bmk _1} - E_{\bmk _2}) t} 
  + \eta \aod{- \bmk _2, \downarrow} \ao{- \bmk _1, \downarrow} 
  \expo{- \tfrac{i}{\hbar} (E_{\bmk _1} - E_{\bmk _2}) t}} \nonumber \\
&\quad + \brac{\cos \theta _{\bmk _1} \sin \theta _{\bmk _2} 
  + \eta \sin \theta _{\bmk _1} \cos \theta _{\bmk _2}} \notag\\
&\qquad\times\brac{\aod{\bmk _1, \uparrow} \aod{- \bmk _2, \downarrow} 
  \expo{\tfrac{i}{\hbar} (E_{\bmk _1} + E_{\bmk _2}) t} 
  + \eta \ao{- \bmk _1, \downarrow} \ao{\bmk _2, \uparrow} 
  \expo{- \tfrac{i}{\hbar} (E_{\bmk _1} + E_{\bmk _2}) t} } 
\Bigr\}\,.
\end{align}

\end{document}

Answer 3

O código-fonte changepage.stymostra

\newenvironment{adjustwidth}[2]{%
  \begin{list}{}{%
    \topsep\z@%
    \listparindent\parindent%
    \parsep\parskip%
    \@ifmtarg{#1}{\setlength{\leftmargin}{\z@}}%
                 {\setlength{\leftmargin}{#1}}%
    \@ifmtarg{#2}{\setlength{\rightmargin}{\z@}}%
                 {\setlength{\rightmargin}{#2}}%
    }
    \item[]}{\end{list}}

(Esses links podem ajudá-lo a entender o código acima:O que \z@ faz?e\topsep, \itemsep, \partopsep e \parsep - o que significa cada um deles (e o que acontece com o fundo)?)

Portanto, o problema não é devido, adjustwidthmas devido a eqnarray. O listambiente fornece uma linha para um item, mas eqnarrayinsere automaticamente uma nova linha, de modo que o espaço é ampliado. As configurações de margem são irrelevantes e o mesmo problema pode ser reproduzido com arquivos itemize. Por exemplo,

Entrada:

\documentclass{article}

\begin{document}

\begin{itemize}
\item
\begin{eqnarray}
f(x) = 1
\end{eqnarray}
\end{itemize}

\begin{itemize}
\item Hello
\begin{eqnarray}
f(x) = 1
\end{eqnarray}
\end{itemize}

\end{document}

Saída:

Então a solução é mover o texto para adjustwidtho ambiente.

Entrada:

\documentclass{article}
\usepackage[top=30truemm,bottom=30truemm,left=25truemm,right=25truemm]{geometry}
\usepackage{changepage}

\begin{document}

\ \\ % normal
Hello World!
\begin{eqnarray}
f(x) = 1
\end{eqnarray}

\ \\ % with adjustwidth
Hello World!
\begin{adjustwidth}{-1cm}{-1cm}
\begin{eqnarray}
f(x) = 1
\end{eqnarray}
\end{adjustwidth}

\ \\ % solution
\begin{adjustwidth}{-1cm}{-1cm}
\hspace{1.0cm}Hello World! % note that this text is INSIDE the environment
\begin{eqnarray}
f(x) = 1
\end{eqnarray}
\end{adjustwidth}

\end{document}

Saída:

Isso é o que eu queria, embora esteja obsoleto eqnarray...