X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=check%2Ftime_vandermonde.cpp;h=f950a36846fe35c65949f5d40dcd1aa3a430ec73;hp=69f8934a44d66801f5839928c157d598123e7a0b;hb=69815a366be5ca81185386d94268d7e7dcce94e3;hpb=af922d5eb36ed70e4a9e3ffaf4c24492cf89a1a6

diff --git a/check/time_vandermonde.cpp b/check/time_vandermonde.cpp
index 69f8934a..f950a368 100644
--- a/check/time_vandermonde.cpp
+++ b/check/time_vandermonde.cpp
@@ -7,7 +7,7 @@
  */
 
 /*
- *  GiNaC Copyright (C) 1999-2000 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2020 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
@@ -21,57 +21,62 @@
  *
  *  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
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-#include "times.h"
+#include "ginac.h"
+#include "timer.h"
+using namespace GiNaC;
+
+#include <iostream>
+#include <vector>
+using namespace std;
 
 static unsigned vandermonde_det(unsigned size)
 {
 	unsigned result = 0;
-	symbol a("a");
-	
+	const symbol a("a");
+
 	// construct Vandermonde matrix:
 	matrix M(size,size);
 	for (unsigned ro=0; ro<size; ++ro) {
 		for (unsigned co=0; co<size; ++co) {
 			if (ro%2)
-				M.set(ro,co,pow(-pow(a,1+ro/2),co));
+				M(ro,co) = pow(-pow(a,1+ro/2),co);
 			else
-				M.set(ro,co,pow(pow(a,1+ro/2),co));
+				M(ro,co) = pow(pow(a,1+ro/2),co);
 		}
 	}
-	
+
 	// compute determinant:
-	ex vdet = M.determinant();
-	
-	// dirty consistency check of result:
-	if (!vdet.subs(a==1).is_zero()) {
-		clog << "Determaint of Vandermonde matrix " << endl
-			 << "M==" << M << endl
-			 << "was miscalculated: det(M)==" << vdet << endl;
+	ex det = M.determinant();
+
+	// check the result:
+	ex vanddet = 1;
+	for (unsigned i=0; i<size; ++i)
+		for (unsigned j=0; j<i; ++j)
+			vanddet *= M(i,1) - M(j,1);
+
+	if (expand(det - vanddet) != 0) {
+		clog << "Determinant of Vandermonde matrix " << endl
+		     << "M==" << M << endl
+		     << "was miscalculated: det(M)==" << det << endl;
 		++result;
 	}
-	
+
 	return result;
 }
 
-unsigned time_vandermonde(void)
+unsigned time_vandermonde()
 {
 	unsigned result = 0;
 	
 	cout << "timing determinant of univariate symbolic Vandermonde matrices" << flush;
-	clog << "-------determinant of univariate symbolic Vandermonde matrices:" << endl;
 	
-	vector<unsigned> sizes;
+	vector<unsigned> sizes = {8, 10, 12, 14};
 	vector<double> times;
 	timer swatch;
 	
-	sizes.push_back(4);
-	sizes.push_back(6);
-	sizes.push_back(8);
-	sizes.push_back(10);
-	
 	for (vector<unsigned>::iterator i=sizes.begin(); i!=sizes.end(); ++i) {
 		int count = 1;
 		swatch.start();
@@ -85,20 +90,23 @@ unsigned time_vandermonde(void)
 		cout << '.' << flush;
 	}
 	
-	if (!result) {
-		cout << " passed ";
-		clog << "(no output)" << endl;
-	} else {
-		cout << " failed ";
-	}
 	// print the report:
 	cout << endl << "	dim:   ";
 	for (vector<unsigned>::iterator i=sizes.begin(); i!=sizes.end(); ++i)
 		cout << '\t' << *i << 'x' << *i;
 	cout << endl << "	time/s:";
 	for (vector<double>::iterator i=times.begin(); i!=times.end(); ++i)
-		cout << '\t' << int(1000*(*i))*0.001;
+		cout << '\t' << *i;
 	cout << endl;
 	
 	return result;
 }
+
+extern void randomify_symbol_serials();
+
+int main(int argc, char** argv)
+{
+	randomify_symbol_serials();
+	cout << setprecision(2) << showpoint;
+	return time_vandermonde();
+}