Re: [NTG-context] METAPOST -- specifying an unknown point coordinate by giving the angle from another known point
Ah, lovely! Who knew there would be so many different solutions? I'm going to use Nicola's solution on this occasion, as it fits my thought process best -- but thanks to Troy as your solutions showed me some other things I didn't know. All the best, James On Fri, Feb 26, 2010 at 9:42 PM, Nicola nvitacolo...@gmail.com wrote: In article 771da05a1002251718l55669a0co770b5a78bed84...@mail.gmail.com, James Fisher jameshfis...@gmail.com wrote: This isn't specifically a ConTeXt question, but via it I've run into a seemingly simple problem in METAPOST that I just can't solve. I'm trying to draw a parallelogram by specifying: (1) the length of sides parallel to the x-axis; (2) the total height of the figure; (3) one of the interior angles. Curiously enough, nobody has posted a solution that uses 'whatever', so here it is: z0 = origin; % bottom left z1 = (5,0); % bottom right y3 = y2 = 10; z3 = z0 + whatever*dir(87); % z3 is obtained by starting at z0 and % moving along dir(87) z2-z1 = whatever*(z3-z0); % The line z1--z2 is parallel to z0--z3 That is, what you were trying to achieve: angle(z3-z0) = dir(87); can be written instead: z3 - z0 = whatever*dir(87); Nicola ___ 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 ___
Re: [NTG-context] METAPOST -- specifying an unknown point coordinate by giving the angle from another known point
In article 771da05a1002251718l55669a0co770b5a78bed84...@mail.gmail.com, James Fisher jameshfis...@gmail.com wrote: This isn't specifically a ConTeXt question, but via it I've run into a seemingly simple problem in METAPOST that I just can't solve. I'm trying to draw a parallelogram by specifying: (1) the length of sides parallel to the x-axis; (2) the total height of the figure; (3) one of the interior angles. Curiously enough, nobody has posted a solution that uses 'whatever', so here it is: z0 = origin;% bottom left z1 = (5,0); % bottom right y3 = y2 = 10; z3 = z0 + whatever*dir(87); % z3 is obtained by starting at z0 and % moving along dir(87) z2-z1 = whatever*(z3-z0); % The line z1--z2 is parallel to z0--z3 That is, what you were trying to achieve: angle(z3-z0) = dir(87); can be written instead: z3 - z0 = whatever*dir(87); Nicola ___ 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 ___
Re: [NTG-context] METAPOST -- specifying an unknown point coordinate by giving the angle from another known point
James, Try this: z0 = origin; z1 = (5,0); z3 = 10*dir(87); z2 = z3-z0+z1; Troy Henderson ___ 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 ___
Re: [NTG-context] METAPOST -- specifying an unknown point coordinate by giving the angle from another known point
James, I apologize, but the previous information that I gave you was wrong. Try this instead: z0 = origin; z1 = (5,0); BL:=87; r:=10/sind(BL); z3 = r*dir(BL); z2 = z3-z0+z1; Troy ___ 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 ___
Re: [NTG-context] METAPOST -- specifying an unknown point coordinate by giving the angle from another known point
Aha! That certainly works. I suspected I would have to fall back on low-level trig :). Many thanks! On Fri, Feb 26, 2010 at 1:44 AM, Troy Henderson thend...@gmail.com wrote: James, I apologize, but the previous information that I gave you was wrong. Try this instead: z0 = origin; z1 = (5,0); BL:=87; r:=10/sind(BL); z3 = r*dir(BL); z2 = z3-z0+z1; Troy ___ 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 ___
Re: [NTG-context] METAPOST -- specifying an unknown point coordinate by giving the angle from another known point
James, How about this. BL:=87; z0=origin; z1=(5,0); z4=dir(BL); % Intermediate point z3=10/y4*z4; z2=z3+z1; or alternatively without having to define z4 BL:=87; z0=origin; z1=(5,0); z3=10/(ypart dir(BL))*dir(BL); z2=z3+z1; ___ 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 ___
