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edvenn_pi.asy

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+// Copyright (c) 2007, Philippe Ivaldi.
+// Version: $Id: edvenn_pi.asy,v 0.0 2007/02/19 17:49:31 Philippe Ivaldi Exp $
+
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or (at
+// your option) any later version.
+
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+// 02110-1301, USA.
+
+// Commentary:
+
+// THANKS:
+
+// BUGS:
+
+// INSTALLATION:
+
+// Code:
+
+
+// Venn diagram // Diagramme de Venn
+// Edwards' construction // Construction d'Edwards
+import roundedpath;
+size(10cm,0);
+path [] EdVenn(int n)
+{
+  path [] opath;
+  if (n>=1)
+    opath.push(shift(-1.4,-.9)*roundedpath(xscale(2.8)*yscale(.9)*unitsquare,.1));
+  if (n>=2)
+    opath.push(shift(0,-.9)*roundedpath(xscale(1.4)*yscale(1.8)*unitsquare,.1));
+  if (n>=3)
+    opath.push(scale(.5)*unitcircle);
+  for (int i=1; i<=n-3; ++i)
+    {
+      pair pcle=point(opath[2],1/(2^i)),
+        ccle=intersectionpoint(pcle--(pcle-dir(opath[2],1/(2^i))), (0,0)--(1,0));
+      path cle=shift(ccle)*scale(abs(pcle-ccle))*unitcircle;
+      real[] p1=intersect(cle, opath[2]);
+      path ocle=subpath(cle,-p1[0],p1[0]);
+      guide tpath;
+      real step=360/(2^i), a=0;
+      for (int j=0; j<2^i; ++j)
+        {
+          tpath=tpath..rotate(a)*ocle;
+          a+=step;
+        }
+      opath.push(tpath..cycle);      
+    }
+    return opath;
+}