]> www.ginac.de Git - ginac.git/blobdiff - check/time_gammaseries.cpp
location of C++ FAQ Lite has changed
[ginac.git] / check / time_gammaseries.cpp
index 3c1ef6856cb8f1af8e227e8120a5f687bc0beec5..afb78395163f4efab5bd8f8288e2ea746dc2eaca 100644 (file)
@@ -3,7 +3,7 @@
  *  Some timings on series expansion of the Gamma function around a pole. */
 
 /*
- *  GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2003 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
@@ -26,46 +26,46 @@ unsigned tgammaseries(unsigned order)
 {
        unsigned result = 0;
        symbol x;
-       
+
        ex myseries = series(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 = evalf(exp(ex(-.57721566490153286*(order-1)))/(order-1));
-       if (evalf(abs((last_coeff-pow(-1,order))/bound)) > numeric(1)) {
+       ex bound = exp(-.57721566490153286*(order-1))/(order-1);
+       if (abs((last_coeff-pow(-1,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;
                ++result;
        }
-       
+
        return result;
 }
 
-unsigned time_gammaseries(void)
+unsigned time_gammaseries()
 {
        unsigned result = 0;
-       
+
        cout << "timing Laurent series expansion of Gamma function" << flush;
        clog << "-------Laurent series expansion of Gamma function:" << endl;
-       
+
        vector<unsigned> sizes;
        vector<double> times;
        timer omega;
-       
+
        sizes.push_back(10);
        sizes.push_back(15);
        sizes.push_back(20);
        sizes.push_back(25);
-       
+
        for (vector<unsigned>::iterator i=sizes.begin(); i!=sizes.end(); ++i) {
                omega.start();
                result += tgammaseries(*i);
                times.push_back(omega.read());
                cout << '.' << flush;
        }
-       
+
        if (!result) {
                cout << " passed ";
                clog << "(no output)" << endl;