Re: [NTG-context] MetaPost transformation
Hello Troy, if you declare a transform variable (e.g., t), it works: transform t; t := identity rotated 270 yscaled 0.5; show identity transformed t; (0,0,0,1,-0.5,0) Greetings Albrecht On Wed, 30 May 2012, Troy Henderson wrote: I've encountered a MetaPost issue, and since many MetaPost users also use ConTeXt (and vice-versa), I am posting this question on both lists. The command show identity rotated 270 yscaled 0.5; outputs (0,0,0,1,-0.5,0) as expected, while the command show identity transformed (0,0,0,1,-0.5,0); errors with --- ! Missing `)' has been inserted. to be read again , l.26 ^^Ishow identity transformed (0,0,0,1, -0.5,0); --- I am using MetaPost 1.504, and the problem seems to be that MetaPost does not like me using the sextuple (0,0,0,1,-0.5,0) directly, but this is the most convenient method for me to describe my transformations. Is this a bug in MetaPost, or am I not allowed to use transformations directly with sextuples? 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 transformation
Albrecht, The issue was to be able to define the transform t using its six components. 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 ___
[NTG-context] MetaPost transformation
I've encountered a MetaPost issue, and since many MetaPost users also use ConTeXt (and vice-versa), I am posting this question on both lists. The command show identity rotated 270 yscaled 0.5; outputs (0,0,0,1,-0.5,0) as expected, while the command show identity transformed (0,0,0,1,-0.5,0); errors with --- ! Missing `)' has been inserted. to be read again , l.26 ^^Ishow identity transformed (0,0,0,1, -0.5,0); --- I am using MetaPost 1.504, and the problem seems to be that MetaPost does not like me using the sextuple (0,0,0,1,-0.5,0) directly, but this is the most convenient method for me to describe my transformations. Is this a bug in MetaPost, or am I not allowed to use transformations directly with sextuples? 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 transformation
On 30-5-2012 23:10, Troy Henderson wrote: I've encountered a MetaPost issue, and since many MetaPost users also use ConTeXt (and vice-versa), I am posting this question on both lists. The command show identity rotated 270 yscaled 0.5; outputs (0,0,0,1,-0.5,0) as expected, while the command show identity transformed (0,0,0,1,-0.5,0); errors with --- ! Missing `)' has been inserted. to be read again , l.26 ^^Ishow identity transformed (0,0,0,1, -0.5,0); --- I am using MetaPost 1.504, and the problem seems to be that MetaPost does not like me using the sextuple (0,0,0,1,-0.5,0) directly, but this is the most convenient method for me to describe my transformations. Is this a bug in MetaPost, or am I not allowed to use transformations directly with sextuples? It looks like sextuples are no basic datatype. I think that the show is just a way to output the internal representation. Of course it would make sense to have sixtuples (I can even think of a generic n-tuple). Hans - Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | voip: 087 875 68 74 | www.pragma-ade.com | www.pragma-pod.nl - ___ 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 transformation
Well then in case anyone needs such a transformation, I've constructed the (non-unique) transformation T t:=angle(f,e); q:=e++f; p:=(c*f-d*e)/q; s:=(c*e+d*f)/(q**2); transform T; T:=identity rotated t xscaled p yscaled q slanted s shifted (a,b); This yields T=(a,b,c,d,e,f). 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 ___
