Otared Kavian wrote :
Hi David and all ConTeXters,
I was away from my e-mail so I am late in answering. Thank you for the file you put on your site. Indeed everything works as intended (the \placeformula no longer advances with each step), and I think one may suggest to Hans to include this in future distributions.
However, in the spirit of ConTeXters who are always asking for a step(!) towards perfectness, I let you know the following drawbacks of the macros:
1) Somehow the \FromStep[n][reserve] changes the internal mechanism of glue or spaces in displayed formulas. So one needs (as you do in your example) to add \; around operators such as +, -, =. Can one avoid this?
I'm sorry, I'm no TeX/ConTeXt guru and I really have no idea of how to achieve this. I think now we need Hans' help. I have indeed noticed that enclosing an operator between braces breaks the spacing system. Try, for instance: \startformula \vec\nabla\cdot\vec u = 0 \stopformula \startformula \vec\nabla\cdot\vec u {=} 0 \stopformula Unfortunately, using \phatom{=} results in the same broken spacing as second formula.
2) When one refers (see example below) with the command (\in[eq:NS]) to an equation which has been introduced with \placeformula[eq:NS] the interaction makes appear the first instance of that formula, which may be incomplete. Could one have a control over this, that is for instance, in this particular case, make appear the completed equation at the end of the slide made with \StartSteps[Navier||Stokes equation]?
Good point! Here's the fix (file updated on my website): 37c37 < \dodoubleempty\doplaceformula[##1]} ---
\dodoubleempty\doplaceformula}
50c50,54 < \dodoubleempty\doplaceformula[####1]} ---
\ifnum\steps@counter=\steps@number% \def\steps@fnext{\dodoubleempty\doplaceformula[####1]}% \else \def\steps@fnext{\dodoubleempty\doplaceformula}% \fi\steps@fnext}
Now we got rid of the duplicate label warnings. I also added your contribution to the usage example. Thank you. Regards, David