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/* Copyright (C) 2004 Viktor T. Toth <http://www.vttoth.com/>
*
* 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.
*
* CTENSOR basics
*/
if get('ctensor,'version)=false then load(ctensor);
("To select a stock metric, use ct_coordsys")$
verbose:false;
ct_coordsys(spherical);
("The metric tensor is stored in the array lg")$
lg;
("A call to cmetric() sets up the inverse and other properties")$
cmetric();
ug;
diagmetric;
("Most metrics are available also as a frame base")$
cframe_flag:true;
ct_coordsys(spherical);
("The inverse frame base is in the array fri; lfg is the frame metric")$
fri;
lfg;
("Now, cmetric computes the frame base, and also the metric")$
cmetric();
fr;
ufg;
lg;
("You can also supply a set of transformation rules to ct_coordsys")$
ct_coordsys([r*cos(theta)*cos(phi),r*cos(theta)*sin(phi),
r*sin(theta),[r,theta,phi]]);
cmetric();
fri;
lg:trigsimp(lg);
/* End of demo -- comment line needed by MAXIMA to resume demo menu */
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