From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.comp.tex.context/76557 Path: news.gmane.org!not-for-mail From: Troy Henderson Newsgroups: gmane.comp.tex.context,gmane.comp.tex.metapost Subject: Re: MetaPost transformation Date: Wed, 30 May 2012 19:56:22 -0500 Message-ID: References: <4FC69178.8020300@wxs.nl> Reply-To: mailing list for ConTeXt users NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1789471472==" X-Trace: dough.gmane.org 1338425831 12884 80.91.229.3 (31 May 2012 00:57:11 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Thu, 31 May 2012 00:57:11 +0000 (UTC) Cc: mailing list for ConTeXt users , MetaPost List To: Hans Hagen Original-X-From: ntg-context-bounces@ntg.nl Thu May 31 02:57:08 2012 Return-path: Envelope-to: gctc-ntg-context-518@m.gmane.org Original-Received: from balder.ntg.nl ([195.12.62.10]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1SZtgs-0002HS-Rk for gctc-ntg-context-518@m.gmane.org; Thu, 31 May 2012 02:56:38 +0200 Original-Received: from localhost (localhost [127.0.0.1]) by balder.ntg.nl (Postfix) with ESMTP id 1CD44101E4; Thu, 31 May 2012 02:56:38 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at balder.ntg.nl Original-Received: from balder.ntg.nl ([127.0.0.1]) by localhost (localhost [127.0.0.1]) (amavisd-new, port 10024) with LMTP id kytXkmuBuA39; Thu, 31 May 2012 02:56:35 +0200 (CEST) Original-Received: from balder.ntg.nl (localhost [127.0.0.1]) by balder.ntg.nl (Postfix) with ESMTP id 9AC1A101E0; Thu, 31 May 2012 02:56:35 +0200 (CEST) Original-Received: from localhost (localhost [127.0.0.1]) by balder.ntg.nl (Postfix) with ESMTP id DF992101E0 for ; Thu, 31 May 2012 02:56:33 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at balder.ntg.nl Original-Received: from balder.ntg.nl ([127.0.0.1]) by localhost (localhost [127.0.0.1]) (amavisd-new, port 10024) with LMTP id W-bRvVFSDHN0 for ; Thu, 31 May 2012 02:56:25 +0200 (CEST) Original-Received: from filter1-til.mf.surf.net (filter1-til.mf.surf.net [194.171.167.217]) by balder.ntg.nl (Postfix) with ESMTP id F2D23101DD for ; Thu, 31 May 2012 02:56:24 +0200 (CEST) Original-Received: from mail-yw0-f41.google.com (mail-yw0-f41.google.com [209.85.213.41]) by filter1-til.mf.surf.net (8.14.3/8.14.3/Debian-9.4) with ESMTP id q4V0uNqi003256 for ; Thu, 31 May 2012 02:56:24 +0200 Original-Received: by yhr47 with SMTP id 47so358521yhr.14 for ; Wed, 30 May 2012 17:56:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=aqdPBRxJ17D3Fd8jo7JDvhpBV4/uHpMMaA87W6Gp2Uc=; b=uMaz3n7nAX4sYG+7H1AWFUAiW3YKw2SKJ/TLRcFYA/9HzcjxCsOTj1aATHhnVfVf1P yjYDB0G0Y1PdXni9JGnFEVf23xnyc7+t3PCBJk35ce3lvRT2lkAIHO2FAlQQ/j5wHyxQ 9faij1lY+XFHpKXdRG6H65VgDEFnzlqGxM6b6MsoOkZgKf6Iz2eiN27Rkn5uMe2q8Jwx G8ZQc5K6Jmwg/ldOdBOLcjK2gwTdk+H5caY8a5WpwTrSgtyXi3uxu4m75u19c2vjBwFG QqVqic5kK/N7L5/vieUM46sEhGzgV6QJxpiIQf1XAcQYQG+lPWZRrSlfK0WsZGTD1YFf FykA== Original-Received: by 10.60.24.67 with SMTP id s3mr17248547oef.54.1338425783050; Wed, 30 May 2012 17:56:23 -0700 (PDT) Original-Received: by 10.76.80.68 with HTTP; Wed, 30 May 2012 17:56:22 -0700 (PDT) In-Reply-To: <4FC69178.8020300@wxs.nl> X-Bayes-Prob: 0.0001 (Score 0, tokens from: @@RPTN) X-CanIt-Geo: ip=209.85.213.41; country=US; region=CA; city=Mountain View; postalcode=94043; latitude=37.4192; longitude=-122.0574; metrocode=807; areacode=650; http://maps.google.com/maps?q=37.4192,-122.0574&z=6 X-CanItPRO-Stream: uu:ntg-context@ntg.nl (inherits from uu:default, base:default) X-Canit-Stats-ID: 0RHgoUnNL - 2d32a9d75d6e - 20120531 (trained as not-spam) X-Scanned-By: CanIt (www . roaringpenguin . com) on 194.171.167.217 X-BeenThere: ntg-context@ntg.nl X-Mailman-Version: 2.1.13 Precedence: list List-Id: mailing list for ConTeXt users List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: ntg-context-bounces@ntg.nl Errors-To: ntg-context-bounces@ntg.nl Xref: news.gmane.org gmane.comp.tex.context:76557 gmane.comp.tex.metapost:2077 Archived-At: --===============1789471472== Content-Type: multipart/alternative; boundary=e89a8ff1caf85b631d04c14a8910 --e89a8ff1caf85b631d04c14a8910 Content-Type: text/plain; charset=ISO-8859-1 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 --e89a8ff1caf85b631d04c14a8910 Content-Type: text/html; charset=ISO-8859-1 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


--e89a8ff1caf85b631d04c14a8910-- --===============1789471472== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline ___________________________________________________________________________________ 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 ___________________________________________________________________________________ --===============1789471472==--