Différences

Ci-dessous, les différences entre deux révisions de la page.

--- 3_domaines_specialises:mathematiques:arguments_contre_eqnarray2 [2018/06/03 15:17]
joseph.wright
+++ — (Version actuelle)
@@ Ligne 1: / Ligne 1: @@
----
-title: Why not use `eqnarray`?
-category: usage
-permalink: /FAQ-eqnarray
----
-The environment `eqnarray` is attractive for the
-occasional user of mathematics in LaTeX documents: it seems to
-allow aligned systems of equations.  Indeed it _does_ supply such
-things, but it makes a serious mess of spacing.  In the system:
-```latex
-\begin{eqnarray}
-  a & = & b + c \\
-  x & = & y - z
-\end{eqnarray}
-```
-the spacing around the "=" signs is _not_ that defined in the
-metrics for the font from which the glyph comes&nbsp;&mdash; it's
-`\arraycolsep`, which may be set to some very odd value for reasons
-associated with real arrays elsewhere in the document.
-The user is far better served by the AMSLaTeX bundle, which
-provides an `align` environment, which is designed with
-the needs of mathematicians in mind (as opposed to the convenience of
-LaTeX programmers).  For this simple case (`align` and
-other AMSLaTeX alignment environments are capable of far greater
-things), code as:
-```latex
-\begin{align}
-  a & = b + c \\
-  x & = y - z
-\end{align}
-```
-The matter is discussed in more detail in a
-[PracTeX journal paper](https://tug.org/pracjourn/2006-4/madsen/madsen.pdf)
-by Lars Madsen; Stefan Kottwitz offers a
-[TeX blog entry](http://texblog.net/latex-archive/maths/eqnarray-align-environment/)
-which includes screen shots of the output, convincingly demonstrating
-the problem.