/** @file time_lw_Pprime.cpp
 *
 *  Test P' from the paper "Comparison of Polynomial-Oriented CAS" by Robert H.
 *  Lewis and Michael Wester. */

/*
 *  GiNaC Copyright (C) 1999-2007 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "times.h"

static unsigned test()
{
	// create the matrix from test P...
	const unsigned n = 10;
	matrix m(n*n+1,n*n+1);
	for (unsigned i=1; i<=n*n; ++i)
		m.set(i-1,i-1,1);
	for (unsigned i=1; i<=n*n; ++i)
		if (!(i%n))
			m.set(i-1,n*n,1);
	for (unsigned i=1; i<=n*n; ++i)
		if (!((i-1)%n))
			m.set(n*n,i-1,n-(i-1)/n);
	for(unsigned i=1; i<=n; ++i)
		for (unsigned j=1; j<=n; ++j)
			if (i-j)
				for (unsigned k=1; k<n; ++k)
					m.set((i-1)*n+k-1,(j-1)*n+k,n+1-j);
	// ...and then another, more dense one:
	matrix m2(m);
	ex a;
	for (unsigned r=0; r<=n*n; ++r) {
		a = m2(r,0);
		for (unsigned c=0; c<n*n; ++c)
			m2.set(r,c,m2(r,c+1));
		m2.set(r,100,a);
	}
	for (unsigned r=0; r<=n*n; ++r)
		for (unsigned c=0; c<=n*n; ++c)
			if (!m(r,c).is_zero())
				m2.set(r,c,m(r,c));
	
	ex det = m2.determinant();
	
	if (det!=numeric("140816284877507872414776")) {
		clog << "det of less sparse rank 101 matrix erroneously returned " << det << endl;
		return 1;
	}
	return 0;
}

unsigned time_lw_Pprime()
{
	unsigned result = 0;
	unsigned count = 0;
	timer rolex;
	double time = .0;
	
	cout << "timing Lewis-Wester test P' (det of less sparse rank 101)" << flush;
	clog << "-------Lewis-Wester test P' (det of less sparse rank 101):" << endl;
	
	rolex.start();
	// correct for very small times:
	do {
		result = test();
		++count;
	} while ((time=rolex.read())<0.1 && !result);
	cout << '.' << flush;
	
	if (!result) {
		cout << " passed ";
		clog << "(no output)" << endl;
	} else {
		cout << " failed ";
	}
	cout << int(1000*(time/count))*0.001 << 's' << endl;
	
	return result;
}