On 24.03.2011 10:57, Otared Kavian wrote:

Hi Stefan,

Thanks for the quick answer and solution!

Your solution works perfectly in mkiv; however typesetting with mkii results in

! Undefined control sequence.

l.3 \startMPdefinitions

Is there a solution with mkii?

Then just drop the MPdefinitions section and put the complete vardef before your normal mp code in the MPcode section. That should work, I think.

May I ask one more question?

In the macro you wrote

Triangle((0cm,0cm), (5cm,0cm), 8cm, 6cm)

one has to specify the double of the length of each side (because a unit circle in MetaPost is a circle having diameter one). Would it be possible to change slightly the lines

Now that's strange... But I see what you mean. I didn't notice.

p := fullcircle scaled la shifted za ;

q := fullcircle scaled lb shifted zb ;

so that la and lb are replaced with their doubled values? I tried

p := fullcircle scaled 2*la shifted za ;

Yeah, you need parentheses here, because otherwise Metapost tries to scale by 2 and then doesn't know how to multiply the result (the path "fullcircle scaled 2") with "la".

p := fullcircle scaled (2 * la) shifted za ;
q := fullcircle scaled (2 * lb) shifted zb ;

but this does not work.

Thanks for your attention: OK

np, Stefan.

On 24 mars 2011, at 10:29, Stefan Müller wrote:

Hi,

what about

\startMPdefinitions

vardef Triangle(expr za, zb, la, lb) =

path p, q ;

pair zc ;

pickup pencircle scaled 2mm ;

drawdot za ;

drawdot zb ;

p := fullcircle scaled la shifted za ;

q := fullcircle scaled lb shifted zb ;

zc = p intersectionpoint q ;

drawdot zc ;

pickup pencircle scaled 1mm ;

za--zb--zc--cycle

enddef;

\stopMPdefinitions

\starttext

\startMPcode

draw Triangle((0cm,0cm), (5cm,0cm), 8cm, 6cm) withcolor blue ;

\stopMPcode

\stoptext

Stefan

On 24.03.2011 09:59, Otared Kavian wrote:

Hi all,

I have a document in which I must draw several triangles for which two summits, say z0, z1, and the length of the two other sides are known, so that the third summit, say z2, is completly determined.

In order to draw one triangle the following works fine:

\setupcolors[state=start]

\starttext

\startMPcode

z0 = (0cm,0cm) ;

z1 = (5cm,0cm) ;

path p, q ;

pickup pencircle scaled 2mm ;

drawdot z0 ;

drawdot z1 ;

p := halfcircle scaled 8 cm ; % twice the length of the second side at z0

p := p shifted z0 ;

q := halfcircle scaled 6 cm ;  % twice the length of the second side at z1

q := q shifted z1  ;

z2 = p intersectionpoint q ;

drawdot z2 ;

pickup pencircle scaled 1mm ;

draw z0--z1--z2--cycle withcolor blue ;

\stopMPcode

\stoptext

However I would like to have a macro, for instance named Triangle, which accepts four arguments z0,z1, length_1, length_2, so that in a MetaPost code i can use

draw Triangle(z0,z1, 4, 3) withcolor blue ;

in order to draw the above triangle.

Has anyone any idea about how to do this?

Thanks in advance for your help: OK

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If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context

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Otared Kavian

Département de Mathématiques

Université de Versailles Saint-Quentin

Bâtiment Fermat

45 avenue des Etats Unis

78035 Versailles cedex

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Secrétariat: +33 1 39 25 46 44

Secrétariat: +33 1 39 25 46 46

e-mail: Otared.Kavian@math.uvsq.fr

___________________________________________________________________________________

If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context

webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net

archive  : http://foundry.supelec.fr/projects/contextrev/

wiki     : http://contextgarden.net

___________________________________________________________________________________

___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
archive  : http://foundry.supelec.fr/projects/contextrev/
wiki     : http://contextgarden.net
___________________________________________________________________________________