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/** @file time_dennyfliegner.cpp
*
* The first test routine implements Denny Fliegner's quick consistency check:
* 1) e = (a0 + a1 + a2 + a3 + ...)^2, in expanded form
* 2) substitute a0 by (-a2 - a3 - ...) in e
* 3) expand e
* after which e should be just a1^2. */
/*
* GiNaC Copyright (C) 1999-2002 Johannes Gutenberg University Mainz, Germany
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "times.h"
static unsigned expand_subs(unsigned size)
{
unsigned result = 0;
// create a vector of size symbols named "a0", "a1", ...
vector<symbol> a;
ex e;
for (unsigned i=0; i<size; ++i) {
ostringstream buf;
buf << "a" << i << ends;
a.push_back(symbol(buf.str()));
e += a[i];
}
ex aux;
// prepare aux so it will swallow anything but a1^2:
aux = -e + a[0] + a[1];
e = pow(e,2).expand().subs(a[0]==aux).expand();
if (e != pow(a[1],2)) {
clog << "Denny Fliegner's quick consistency check erroneously returned "
<< e << "." << endl;
++result;
}
return result;
}
unsigned time_dennyfliegner(void)
{
unsigned result = 0;
cout << "timing commutative expansion and substitution" << flush;
clog << "-------commutative expansion and substitution:" << endl;
vector<unsigned> sizes;
vector<double> times;
timer breitling;
sizes.push_back(25);
sizes.push_back(50);
sizes.push_back(100);
sizes.push_back(200);
for (vector<unsigned>::iterator i=sizes.begin(); i!=sizes.end(); ++i) {
breitling.start();
result += expand_subs(*i);
times.push_back(breitling.read());
cout << '.' << flush;
}
if (!result) {
cout << " passed ";
clog << "(no output)" << endl;
} else {
cout << " failed ";
}
// print the report:
cout << endl << " size: ";
for (vector<unsigned>::iterator i=sizes.begin(); i!=sizes.end(); ++i)
cout << '\t' << (*i);
cout << endl << " time/s:";
for (vector<double>::iterator i=times.begin(); i!=times.end(); ++i)
cout << '\t' << int(1000*(*i))*0.001;
cout << endl;
return result;
}
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