%% %% Ein Beispiel der DANTE-Edition %% %% 2. Auflage %% %% Beispiel 15-02-28 auf Seite 726. %% %% Copyright (C) 2016 Herbert Voss %% %% It may be distributed and/or modified under the conditions %% of the LaTeX Project Public License, either version 1.3 %% of this license or (at your option) any later version. %% %% See http://www.latex-project.org/lppl.txt for details. %% %% %% ==== % Show page(s) 1 %% defaultfont:="ptmr8r"; warningcheck:=0; % --- start of displayed preamble in the book --- % --- end of displayed preamble in the book --- % % beginfig(1) def compute_curve(suffix f)(expr xmin,xmax,xinc) = ( (xmin,f(xmin)) for x=xmin+xinc step xinc until xmax: ..(x,f(x)) endfor ) enddef; vardef f(expr x)=x**2+1 enddef; vardef g(expr x)=2.6-(x-1)**2 enddef; path p, q; p:=compute_curve(f,-1,1.5,0.1) scaled 1cm; q:=compute_curve(g,-0.5,2,0.1) scaled 1cm; fill buildcycle(p,reverse q) withcolor red; draw p withpen pencircle scaled 1bp; draw q withpen pencircle scaled 1bp; drawarrow (-1cm,0)--(2cm,0);label.rt("x",(2cm,0)); drawarrow (0,0)--(0,3cm);label.top("y",(0,3cm)); endfig; end;