* Some timings on series expansion of the Gamma function around a pole. */
/*
- * GiNaC Copyright (C) 1999-2007 Johannes Gutenberg University Mainz, Germany
+ * GiNaC Copyright (C) 1999-2017 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
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
-#include <iostream>
-#include <vector>
#include "ginac.h"
#include "timer.h"
-using namespace std;
using namespace GiNaC;
+#include <iostream>
+#include <vector>
+using namespace std;
+
unsigned tgammaseries(unsigned order)
{
unsigned result = 0;
symbol x;
- ex myseries = series(tgamma(x),x==0,order);
+ ex myseries = series(GiNaC::tgamma(x),x==0,order);
// compute the last coefficient numerically:
ex last_coeff = myseries.coeff(x,order-1).evalf();
// compute a bound for that coefficient using a variation of the leading
// term in Stirling's formula:
ex bound = exp(-.57721566490153286*(order-1))/(order-1);
- if (abs((last_coeff-pow(-1,order))/bound) > 1) {
+ if (abs((last_coeff-pow(-1,ex(order)))/bound) > 1) {
clog << "The " << order-1
<< "th order coefficient in the power series expansion of tgamma(0) was erroneously found to be "
<< last_coeff << ", violating a simple estimate." << endl;
cout << "timing Laurent series expansion of Gamma function" << flush;
- vector<unsigned> sizes;
+ vector<unsigned> sizes = {20, 25, 30, 35};
vector<double> times;
timer omega;
- sizes.push_back(20);
- sizes.push_back(25);
- sizes.push_back(30);
- sizes.push_back(35);
-
for (vector<unsigned>::iterator i=sizes.begin(); i!=sizes.end(); ++i) {
omega.start();
result += tgammaseries(*i);