%%%% prbla_00.ldf %%%% Created by Laurence D. Finston (LDF) Wed Nov 9 18:12:16 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 The Free Software Foundation %%%% 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 2 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. %%%% It is also available from %%%% http://www.dante.de/software/ctan/, the Dante www-server %%%% and from http://wwwuser.gwdg.de/~lfinsto1, %%%% the author's website. %%%% Please send bug reports to lfinsto1@gwdg.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 %%%% Kreuzbergring 41 %%%% D-37075 Goettingen %%%% Germany %%%% lfinsto1@gwdg.de %%%% s246794@stud.uni-goettingen.de %% Run these commands: %% 3dldf prbla_00.ldf %% mpost prbla_00 %% tex prbla_00.txt %% dvips -o prbla_00.ps prbla_00.dvi %% gv prbla_00.ps & verbatim_metapost "ahlength := .25cm;"; verbatim_metapost "verbatimtex \magnification=\magstep5 \font\large=cmr17 etex"; focus f; set f with_position (0, 50, -20) with_direction (0, 50, 100) with_distance 10; picture axis_picture; %% **** (4) axis_picture. beginfig(0); pickup pencircle scaled (1mm, 1mm); axis_x_lft := 10; axis_x_rt := 10; axis_y_bot := 10; axis_y_top := 10; axis_z_front := 10; axis_z_back := 10; drawdblarrow (-axis_x_lft, 0) -- (axis_x_rt, 0); label.bot("x", (axis_x_rt, 0, -.1)); %drawdblarrow (0, -axis_y_bot) -- (0, axis_y_top); %label.lft("y", (0, axis_y_top)); drawdblarrow (0, 0, -axis_z_front) -- (0, 0, axis_z_back); label.lft("z", (0, 0, axis_z_back)); axis_picture := current_picture; clear current_picture; endfig; beginfig(1); parabola p; point vertex; vertex := (-5, 0, 2); set p with_vertex vertex % with_focus p_focus with_extent 5cm; point p_f; point vertex; draw p with_color blue; %dotlabel.lft(0, p); pickup pencircle scaled (2mm, 2mm); vertex := get_vertex p; drawdot vertex; label.lft("vertex", vertex); p_f := get_focus p; drawdot p_f; label.rt("focus", p_f); label("{\large PARABOLA}", (5, 0, -5)); output axis_picture with_projection parallel_x_z; endfig with_projection parallel_x_z; verbatim_metapost "end"; end;