\counterwithin (which
establishes this nested numbering relationship) and
\counterwithout (which undoes it).
So if you have figures numbered by chapter as 1.1, 1.2, 2.1, …,
the command
\counterwithout{figure}{chapter}
will convert them to figures 1, 2, 3, …. (Note that the command
has also removed the chapter number from the counter’s definition.)
More elaborate use could change things numbered per section to things
numbered per chapter:
\counterwithout{equation}{section}
\counterwithin{equation}{chapter}
(assuming there was a class that did such a thing in the first place...)
The chngcntr approach doesn’t involve much programming, and
the enthusiastic LaTeX programmer might choose to try the technique
that we had to use before the advent of chngcntr. Each of
the packages removefr and remreset defines a
\@removefromreset command, and having included the package one
writes something like:
\makeatletter
\@removefromreset{figure}{chapter}
\makeatother
and the automatic renumbering stops. You may then need to redefine the
way in which the figure number (in this case) is printed:
\makeatletter
\renewcommand{\thefigure}{\@arabic\c@figure}
\makeatother
(remember to do the whole job, for every counter you want to
manipulate, within \makeatletter … \makeatother).
This technique, too, may be used to change where in a multilevel
structure a counter is reset. Suppose your class numbers figures as
<chapter>.<section>.<figure>, and you want figures
numbered per chapter, try:
\makeatletter
\@removefromreset{figure}{section}
\@addtoreset{figure}{chapter}
\renewcommand{\thefigure}{\thechapter.\@arabic\c@figure}
\makeatother
(the command \@addtoreset is a part of LaTeX itself).
\input{removefr})
This question on the Web: http://www.tex.ac.uk/cgi-bin/texfaq2html?label=running-nos