Re: [NTG-context] Mathematical MetaFun Mania

15 Dec 2022

      Hi Hans,

Thanks for the new release and the nice anchoring features.

I played a little bit with these, and noticed some issues: in the following example, linking the bottom bounds of the integral signs is fine (as long as numbers are put there), but for the upper bounds, the \infty and \pi/2 are not accepted (nor is any letter or greek symbol), but if one replaces \infty and \pi/2 with numbers, then the link between the upper bounds is shown. (In this example the links are invading the text, but probably this is due to the fact that I just copied the Metapost snippet you sent to Gavin).

Best regards: Otared

% begin anchoring-integrals.tex
\starttext

\startMPpositiongraphic{mypos:boxanchor:top}
	begingroup ;
		save f, t, p ; 
		pair f, t ; 
		path p ;
		f := positionxy(mpvars("from")) ;
		t := positionxy(mpvars("to")) ;
		p := f { up } .. t ;
		drawarrow p
			withpen pencircle scaled mpvard "rulethickness"
			withcolor mpvars "linecolor" ; % historically different names
		positioninregion ;
	endgroup ;
\stopMPpositiongraphic

\startMPpositiongraphic{mypos:boxanchor:bottom}
	begingroup ;
		save f, t, p ; 
		pair f, t ; 
		path p ;
		f := positionxy(mpvars("from")) ;
		t := positionxy(mpvars("to")) ;
		p := f { down } .. t ;
		drawarrow p
			withpen pencircle scaled mpvard "myrulethickness"
			withcolor mpvars "linecolor" ; % historically different names
		positioninregion ;
	endgroup ;
\stopMPpositiongraphic

\input thuan.tex

\startboxanchoring[+]
\connectboxanchors[top][top]
	[distance=1ex,
	rulethickness=1pt,
	rulecolor=darkgreen,
	mp=mypos:boxanchor:top]{b1}{b3}

\connectboxanchors[bottom][bottom]
	[distance=1ex,
	myrulethickness=1pt,
	rulecolor=darkred,
	mp=mypos:boxanchor:bottom]{b2}{b4}

\startformula
\int_{\mathboxanchored[nucleus]{b2}0}^{\mathboxanchored[nucleus]{b1}\infty} \frac{\dd x}{1 + x^2} = \int_{\mathboxanchored[nucleus]{b4}0}^{\mathboxanchored[nucleus]{b3}\pi/2}(1 + \tan(\theta)^2)\frac{\dd \theta}{1 + \tan(\theta)^2} = \frac{\pi}{2}
\stopformula
\input thuan.tex
\stopboxanchoring

\stoptext
% end anchoring-integrals
...
On 15 Dec 2022, at 18:21, Hans Hagen via ntg-context  wrote:
On 12/15/2022 5:15 PM, Gavin wrote:
...
Hi Hans and List,
...
...
2) Can I tell \connectboxanchors to use my MetaPost code and pass key=value pairs like I do with \setMPpositiongraphic?
see attached ... the 'cross pages' feature is in the upcoming
This indeed passes key=value pairs, but I cannot get it to pass mine. Is there some intermediate step? Your example has a key=value pair in \connectboxanchors and which is accessed in the MetaPost code. The pair, and MetaPost code are:
  rulethickness=1pt
  mpvard “rulethickness"
However, if I change the pair and MPcode to (see attached example for full code)
  myrulethickness=1pt
  mpvard “myrulethickness"
it doesn’t work. Similarly, you have a pair and MPcode that don’t match.
  rulecolor=darkgreen
  mpvars "linecolor"
This may be a historical fluke, but it suggests that there is some intermediate translation that I am missing. Any way I can name and pass by own key=value pairs?
I updated lmtx so you can test it again.
Hans
ps. For the adventurous some bonus experiment in the engine:
\def\ccc#1#2#3#4#5#6#7#8#9#A#B#C#D#E#F%
 {\def\ddd{#A-#D-#E/#F-#4-#1}%
  #A-#D-#E/#F-#4-#1+\ddd}
so, upto 15 arguments:
[[\ccc123456789abcdef]]
(not that we need it in the context core, so more a gimmick for users and it fits the much is already hex approach)
Hans
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                                         Hans Hagen | PRAGMA ADE
             Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
      tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
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Otared Kavian
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