%%%% hyprb_01.ldf %%%% Created by Laurence D. Finston (LDF) Sun Nov 27 18:01:02 CET 2005 %% * (1) Copyright and License. %%%% This file is part of GNU 3DLDF, a package for three-dimensional drawing. !%%%% Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 The Free Software Foundation, Inc. %%%% GNU 3DLDF 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 3 of the License, or %%%% (at your option) any later version. %%%% GNU 3DLDF 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 GNU 3DLDF; if not, write to the Free Software %%%% Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA %%%% GNU 3DLDF is a GNU package. %%%% It is part of the GNU Project of the %%%% Free Software Foundation %%%% and is published under the GNU General Public License. %%%% See the website http://www.gnu.org %%%% for more information. %%%% GNU 3DLDF is available for downloading from %%%% http://www.gnu.org/software/3dldf/LDF.html. %%%% Please send bug reports to Laurence.Finston@gmx.de %%%% The mailing list help-3dldf@gnu.org is available for people to %%%% ask other users for help. %%%% The mailing list info-3dldf@gnu.org is for the maintainer of %%%% GNU 3DLDF to send announcements to users. %%%% To subscribe to these mailing lists, send an %%%% email with ``subscribe '' as the subject. %%%% The author can be contacted at: %%%% Laurence D. Finston %%%% c/o The Free Software Foundation, Inc. %%%% 51 Franklin St, Fifth Floor %%%% Boston, MA 02110-1301 %%%% USA %%%% Laurence.Finston@gmx.de %% Run these commands: %% 3dldf hyprb_01.ldf %% mpost hyprb_01 %% tex hyprb_01.txt %% dvips -o hyprb_01.ps hyprb_01.dvi %% gv hyprb_01.ps & %% *** (3) The intersection points of a `hyperbola' `h' and a linear `path' `q', %% such that `h' and `q' are coplanar, and the slope of `q' is finite %% and non-zero. %% LDF 2005.11.27. verbatim_metapost "verbatimtex \magnification=\magstep5 \font\large=cmr12 etex"; pickup pencircle scaled (.75mm, .75mm); beginfig(1); hyperbola h; set h with_max_extent 10; path q[]; q0 := (-12, 0) -- (12, 0) rotated (0, 30, 0) shifted 1; draw h; draw q0; bool_point_vector bpv; bpv := h intersection_points q0; pen p; p := pencircle scaled (1.5mm, 1.5mm); if size bpv > 0: point A; A := bpv0; drawdot bpv0 with_color red with_pen p; label.urt("$i_0$", A shifted (0, 0, .2)); fi; if size bpv > 1: drawdot bpv1 with_color red with_pen p; label.ulft("$i_1$", bpv1); fi; endfig with_projection parallel_x_z; verbatim_metapost "end"; end;