summaryrefslogtreecommitdiff
path: root/macros/latex/contrib/subeqnarray/subeqnarray.dtx
blob: 5b3555c31200c8f9a2f9d97dd424a13c869e464e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
% \iffalse meta-comment
%
% Copyright 1994-2004 Johannes Braams.  All rights reserved.
% 
% This file is part of the subeqnarray package.
% ---------------------------------------------
% 
% It may be distributed and/or modified under the
% conditions of the LaTeX Project Public License, either version 1.3
% of this license or (at your option) any later version.
% The latest version of this license is in
%   http://www.latex-project.org/lppl.txt
% and version 1.3 or later is part of all distributions of LaTeX
% version 2003/12/01 or later.
% 
% This work has the LPPL maintenance status "maintained".
% 
% The Current Maintainer of this work is Johannes Braams.
% 
% The list of all files belonging to the subeqnarray package is
% given in the file `manifest.txt'.
% 
% The list of derived (unpacked) files belonging to the distribution
% and covered by LPPL is defined by the unpacking scripts (with
% extension .ins) which are part of the distribution.
% \fi
% \CheckSum{259}
%\iffalse
%
% Subeqnarray package to use with LaTeX2e
%
%% Copyright (C) 1988--2004 by Johannes Braams, 
%%                          all rights resserved
%%
%% Error reports please to: J. Braams
%%                          TeXniek
%%                          Kooienswater 62
%%                          2715 AJ Zoetermeer
%%                          The Netherlands
%%                  Email:  texniek at braams.cistron.nl
%
% \section{Producing the documentation}
%
%    A short driver is provided that can be extracted if necessary by
%    the \textsf{DocStrip} program provided with \LaTeXe.
%<*dtx>
\ProvidesFile{subeqnarray.dtx}
%</dtx>
%<package>\NeedsTeXFormat{LaTeX2e}[1998/06/01]
%<package>\ProvidesPackage{subeqnarray}
%<sample>\ProvidesFile{subeqnarray.tex}
%<driver>\ProvidesFile{subeqnarray.drv}
%\ProvidesFile{subeqnarray.dtx}
              [2004/04/15 v2.1c subeqnarray package]           
%<*driver>
\documentclass{ltxdoc}

\pagestyle{myheadings}
\EnableCrossrefs
\CodelineIndex
\RecordChanges
\newcommand\Lopt[1]{\textsf{#1}}
\makeatletter
\renewenvironment{theglossary}{%
    \glossary@prologue%
    \GlossaryParms \let\item\@idxitem \ignorespaces}%
   {}
\makeatother
\begin{document}

\DocInput{subeqnarray.dtx}
\newpage
\PrintIndex
\PrintChanges
\end{document}
%</driver>
%    \end{macrocode}
%\fi
%
% \GetFileInfo{subeqnarray.dtx}
% \title{Numbering individual lines of equation array's}
%
% \author{Johannes Braams\\
%         \TeX niek\\
%         Kersengaarde 33\\
%         2723 BP Zoetermeer\\
%         The Netherlands\\
%         Internet: \texttt{TeXniek at braams.cistron.nl}}
%
% \date{\filedate}
%
% \markboth
%      {subeqnarray package version \fileversion\space as of \filedate}
%      {subeqnarray package version \fileversion\space as of \filedate}
%
% \maketitle
%
%
%    This package defines the \texttt{subeqnarray} and
%    \texttt{subeqnarray*} environments, which behave like the
%    equivalent \texttt{eqnarray} and \texttt{eqnarray*} environments,
%    except that the individual lines are numbered like 1a, 1b, 1c,
%    etc.
%
%    To refer to these numbers an extra label command |\slabel|
%    has been defined.
%
%    Many of this code was taken from \texttt{latex.tex} and modified
%    for  this purpose.
%
% \StopEventually{}
%
% \changes{1.1}{1988/12/22}{Fixed bug in subeqnarray* environment}
% \changes{2.0}{1993/11/02}{Added support for the leqno option}
% \changes{2.0}{1993/11/02}{Added support for the fleqn  option}
% \changes{2.1}{1994/02/09}{Upgrade for LaTeX2e}
% \changes{2.1b}{1999/03/03}{Changed licensing remarks to use LPPL}
% \changes{2.1c}{2004/04/15}{Updated address information}
%
% \section{Initial Code}
%
% \begin{macro}{\c@subequation}
%    We need to allocate a new counter for the \texttt{subequation}
%    environment. It is reset by the \texttt{equation} counter.
%    \begin{macrocode}
%<*package>
\newcounter{subequation}[equation]
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\thesubequation}
%    The representation o the counter \texttt{subequation} includes
%    the \texttt{equation} counter
%    \begin{macrocode}
\def\thesubequation{\theequation\alph{subequation}}
%    \end{macrocode}
% \end{macro}
%
% \section{Option Handling}
%
%    The standard \LaTeX\ options \Lopt{leqno} and \Lopt{fleqn} are
%    recognised by this package.
%    \begin{macrocode}
%
%    When \Lopt{leqno} is used the equation numbers should appear on
%    the left side of the equation. The numbers are generated by
%    |\@subeqnnum| which needs a different definition to acheive this
%    effect.
%    \begin{macrocode}
\DeclareOption{leqno}{%
  \def\@subeqnnum{\hbox to .01\p@{}\rlap{\reset@font\rmfamily
        \hskip -\displaywidth(\thesubequation)}}}
%    \end{macrocode}
%    The default definition of |\@subeqnnum|.
%    \begin{macrocode}
\DeclareOption{reqno}{%
  \def\@subeqnnum{{\reset@font\rmfamily (\thesubequation)}}}
%    \end{macrocode}
%
%    When the option \Lopt{fleqn} is used, the equations have to be
%    printed flush left, with an indent of |\mathindent|; the
%    equations are seperated from the surrounding text by |\topsep|
%    (plus |\partopsep| if necessary) and the width of the display is
%    |\linewidth|.
%    \begin{macrocode}
\DeclareOption{fleqn}{%
  \def\subeqn@start{%
    \tabskip\mathindent
    \abovedisplayskip\topsep
    \ifvmode\advance\abovedisplayskip\partopsep\fi
    \belowdisplayskip\abovedisplayskip
    \belowdisplayshortskip\abovedisplayskip
    \abovedisplayshortskip\abovedisplayskip
    $$\everycr{}\halign to \linewidth}}% $$
%    \end{macrocode}
%
%    The default will be to have displayed equations to the width of
%    |\displaywidth|.
%    \begin{macrocode}
\DeclareOption{deqn}{%
  \def\subeqn@start{%
    \tabskip\@centering
    $$\everycr{}\halign to \displaywidth}}% $$
%    \end{macrocode}
%
%    We don't support any other options
%    \begin{macrocode}
\DeclareOption*{\OptionNotUsed}
%    \end{macrocode}
%
% \section{Executing Options}
%
%    Make sure the |\@eqnnum| is defined by specifying \Lopt{reqno} as
%    a default option. Specifying \Lopt{deqn} as a default option
%    defines |\subeqn@start|.
%    \begin{macrocode}
\ExecuteOptions{reqno,deqn}
%    \end{macrocode}
%
%    Now see if the use specified any options.
%    \begin{macrocode}
\ProcessOptions
%    \end{macrocode}
%
% \section{The main code}
%
% \begin{macro}{\slabel}
%    A new label command to refer to subequations. It works
%    like the |\label| command and was taken from \texttt{latex.tex}.
%
%  |\slabel{FOO}| writes the following on file |\@auxout|
%
%  |\newlabel{FOO}{{eval(\@currentlabel)}{eval(\thepage)}}|
%
%    \begin{macrocode}
\newcommand\slabel[1]{%
  \@bsphack
  \if@filesw
    {\let\thepage\relax
     \def\protect{\noexpand\noexpand\noexpand}%
     \edef\@tempa{\write\@auxout{\string
        \newlabel{#1}{{\thesubequation}{\thepage}}}}%
     \expandafter}\@tempa
     \if@nobreak \ifvmode\nobreak\fi\fi
  \fi\@esphack}
%    \end{macrocode}
% \end{macro}
%
% \begin{environment}{subeqnarray}
%    The \texttt{subeqnarray} environment steps the equation counter,
%    sets the subequation counter equal to 1 and behaves much like the
%    \texttt{eqnarray} environment. Note the |\@currentlabel| is
%    defined to use the equation counter. This is done so that an
%    entire array an be referred to using the value of the equation
%    counter. Hence the need for the |\slabel| command.
%
%    \begin{macrocode}
\newenvironment{subeqnarray}%
   {\stepcounter{equation}%
    \def\@currentlabel{\p@equation\theequation}%
    \global\c@subequation\@ne
    \global\@eqnswtrue\m@th
    \global\@eqcnt\z@\let\\\@subeqncr
    \subeqn@start
     \bgroup\hskip\@centering
      $\displaystyle\tabskip\z@skip{##}$\@eqnsel
      &\global\@eqcnt\@ne \hskip \tw@\arraycolsep \hfil${##}$\hfil
      &\global\@eqcnt\tw@ \hskip \tw@\arraycolsep
         $\displaystyle{##}$\hfil \tabskip\@centering
      &\global\@eqcnt\thr@@
         \hbox to\z@\bgroup\hss##\egroup\tabskip\z@skip\cr}
   {\@@subeqncr\egroup $$\global\@ignoretrue}
%    \end{macrocode}
% \end{environment}
%
% \begin{macro}{\@subeqncr}
%    These macros handle the user command |\\|; they are adapted from
%    the ones used or the \texttt{eqnarray} environment.
%
%    First the presence of a \texttt{*} detected and the right penalty
%    selected.
%    \begin{macrocode}
\def\@subeqncr{{\ifnum0=`}\fi\@ifstar{\global\@eqpen\@M
    \@ysubeqncr}{\global\@eqpen\interdisplaylinepenalty \@ysubeqncr}}
%    \end{macrocode}
%
% \begin{macro}{@ysubeqncr}
%    This macro is called by |\@subeqncr| and checks if the user
%    requested any extra vertical space. It calls |\@xsubeqncr| with
%    the wanted amount of space as its argument.
%    \begin{macrocode}
\def\@ysubeqncr{\@ifnextchar [{\@xsubeqncr}{\@xsubeqncr[\z@skip]}}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\@xsubeqncr}
%    This macro calls |\@@subeqncr| to put in extra |&|'s if needed,
%    generating an error if the number of columns is too large. Then
%    the penalty selected earlier and the white space requested are
%    inserted.
%    \begin{macrocode}
\def\@xsubeqncr[#1]{\ifnum0=`{\fi}\@@subeqncr
   \noalign{\penalty\@eqpen\vskip\jot\vskip #1\relax}}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\@@subeqncr}
%    Ceck the number of columns, and insert extra |&| if needed. If
%    there appear to be more than 3 columns an error is signalled.
%    \begin{macrocode}
\def\@@subeqncr{\let\@tempa\relax
    \ifcase\@eqcnt \def\@tempa{& & &}\or \def\@tempa{& &}
      \or \def\@tempa{&}\else
       \let\@tempa\@empty
       \@latexerr{Too many columns in subeqnarray environment}\@ehc\fi
     \@tempa \if@eqnsw\@subeqnnum\refstepcounter{subequation}\fi
     \global\@eqnswtrue\global\@eqcnt\z@\cr}
%    \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{environment}{subeqnarray*}
%    This environment is basically the same as the \texttt{eqnarray}
%    environment, but it is provided just or completeness.
%    \begin{macrocode}
\newenvironment{subeqnarray*}%
  {\def\@subeqncr{\nonumber\@ssubeqncr}\subeqnarray}
  {\global\advance\c@equation\m@ne\nonumber\endsubeqnarray}
%    \end{macrocode}
% \end{environment}
%
% \begin{macro}{\@ssubeqncr}
%    This is used in the \texttt{esubqnarray*} environment.
%    \begin{macrocode}
\let\@ssubeqncr\@subeqncr
%</package>
%<*sample>
%    \end{macrocode}
% \end{macro}
%
% \section{An example of the use of this package}
%
%    When you run the following document through \LaTeX\ you will see
%    the differene between the \texttt{subeqnarray} and
%    \texttt{eqnarray} environments.
%    \begin{macrocode}
%<*sample>
\documentclass[fleqn]{article}
\usepackage{subeqnarray}
\begin{document}
This document shows an example of the use of the \emph{subeqnarray}
environment. Here is one:
\begin{subeqnarray}
\label{eqw}
\slabel{eq0}
 x & = & a \times b \\
\slabel{eq1}
 & = & z + t\\
\slabel{eq2}
 & = & z + t
\end{subeqnarray}
The first equation is number~\ref{eq0}, the last is~\ref{eq2}. The
equation as a whole can be referred to as equation~\ref{eqw}.

To show that equation numbers behave normally, here's an
\emph{eqnarray} environment.
\begin{eqnarray}
\label{eq10}
 x & = & a \times b \\
\label{eq11}
 & = & z + t\\
\label{eq12}
 & = & z + t
\end{eqnarray}

These are equations~\ref{eq10},~\ref{eq11} and~\ref{eq12}.
\end{document}
%</sample>
%    \end{macrocode}
%
% \Finale
\endinput
%
%% \CharacterTable
%%  {Upper-case    \A\B\C\D\E\F\G\H\I\J\K\L\M\N\O\P\Q\R\S\T\U\V\W\X\Y\Z
%%   Lower-case    \a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z
%%   Digits        \0\1\2\3\4\5\6\7\8\9
%%   Exclamation   \!     Double quote  \"     Hash (number) \#
%%   Dollar        \$     Percent       \%     Ampersand     \&
%%   Acute accent  \'     Left paren    \(     Right paren   \)
%%   Asterisk      \*     Plus          \+     Comma         \,
%%   Minus         \-     Point         \.     Solidus       \/
%%   Colon         \:     Semicolon     \;     Less than     \<
%%   Equals        \=     Greater than  \>     Question mark \?
%%   Commercial at \@     Left bracket  \[     Backslash     \\
%%   Right bracket \]     Circumflex    \^     Underscore    \_
%%   Grave accent  \`     Left brace    \{     Vertical bar  \|
%%   Right brace   \}     Tilde         \~}
%%