diff -r d59bea55db9b -r c445c931472f examples/graph.mod
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/graph.mod	Mon Dec 06 13:09:21 2010 +0100
@@ -0,0 +1,98 @@
+/* graph.mod - graph visualization */
+
+/* Written in GNU MathProg by Andrew Makhorin <mao@gnu.org> */
+
+/* This model creates a picture in EPS format to visualize a graph. */
+
+param file, symbolic, default "graph.eps";
+/* output file to write the picture */
+
+param R, default 2;
+/* radius to draw vertices, in mm */
+
+param n, integer, > 0;
+/* number of vertices */
+
+set V, default 1..n;
+/* set of vertices */
+
+set E, within V cross V;
+/* set of edges */
+
+param x{i in V}, default 50 * cos((i - 1) / card(V) * 8 * atan(1));
+param y{i in V}, default 50 * sin((i - 1) / card(V) * 8 * atan(1));
+/* x[i] and y[i] are coordinates of node i, in mm */
+
+param x0 := (min{i in V} x[i]) - R - 3.0;
+param y0 := (min{i in V} y[i]) - R - 3.0;
+param x1 := (max{i in V} x[i]) + R + 3.0;
+param y1 := (max{i in V} y[i]) + R + 3.0;
+
+printf "%%!PS-Adobe-3.0 EPSF-3.0\n" > file;
+printf "%%%%BoundingBox: 0 0 %d %d\n",
+      (72 / 25.4) * (x1 - x0), (72 / 25.4) * (y1 - y0) >> file;
+printf "/Helvetica findfont 6 scalefont setfont\n" >> file;
+printf "/mm { 72 mul 25.4 div } def\n" >> file;
+
+for {(i,j) in E}
+{     printf "newpath\n" >> file;
+      printf "%g mm %g mm moveto\n", x[i] - x0, y[i] - y0 >> file;
+      printf "%g mm %g mm lineto\n", x[j] - x0, y[j] - y0 >> file;
+      printf "closepath\n" >> file;
+      printf "stroke\n" >> file;
+}
+
+for {i in V}
+{     printf "newpath\n" >> file;
+      printf "%g mm %g mm %g mm 0 360 arc\n",
+         x[i] - x0, y[i] - y0, R >> file;
+      printf "closepath\n" >> file;
+      printf "gsave 1 1 1 setrgbcolor fill grestore\n" >> file;
+      printf "stroke\n" >> file;
+      printf "%g mm %g mm moveto\n",
+         x[i] - (if i <= 9 then 1.2 else 1.8) - x0,
+         y[i] - 0.8 - y0 >> file;
+      printf "( %d ) show\n", i >> file;
+}
+
+printf "showpage\n" >> file;
+printf "%%%%EOF\n" >> file;
+
+data;
+
+param
+:  V  :  x     y :=
+   1     0    40
+   2    38    12
+   3    24   -32
+   4   -24   -32
+   5   -38    12
+   6   -19    26
+   7    19    26
+   8    31   -10
+   9     0   -32
+  10   -31   -10
+  11    -9    12
+  12     9    12
+  13    14    -5
+  14     0   -15
+  15   -14    -5
+  16     0     0 ;
+
+set E :=
+   (1,*)  6 10 16 12  7
+   (2,*)  7  6 16 13  8
+   (3,*)  8  7 16 14  9
+   (4,*)  9  8 16 15 10
+   (5,*) 10  9 16 11  6
+   (6,*) 14
+   (7,*) 15
+   (8,*) 11
+   (9,*) 12
+  (10,*) 13
+  (11,*) 12 15
+  (12,*) 13
+  (13,*) 14
+  (14,*) 15 ;
+
+end;