Math & Science ⇒ Numbering macro

[PJH]

LaTeX lets you \label an equation then later \ref it.

I want to write two macros, \mylabel and \myref which do the following:

\mylabel behaves like \label if the equation is actually referred to in the document (using \myref). If not it behaves like \nonumber.

I did this a long time ago in TeX. It required TeX to be run three times and worked as follows:

Sweep 1: \myref{eq1} outputs to a file the fact that eq1 is referenced.
Sweep 2: \mylabel labels eq1 and any others that are referenced - it knows this from the output of Sweep 1.
Sweep 3: \myref acts like \ref.

I dont know how to do this in LaTeX. Anyone know how?
Thanks

Phil

[Juanjo]

I think what you pretend has already been implemented in the mathtools package. Check section 3.2 of the manual.

[PJH]

Thanks

Following on from your suggestion, I also found this which does the job:
http://www.cs.brown.edu/system/software ... doceqn.pdf

[localghost]

If that solves the problem, then please mark the topic (not the last post) accordingly as written in Section 3 of the Board Rules (to be read before posting).


Best regards and welcome to the board
Thorsten