* Series expansion test (Laurent and Taylor series). */
/*
- * GiNaC Copyright (C) 1999-2000 Johannes Gutenberg University Mainz, Germany
+ * GiNaC Copyright (C) 1999-2019 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
*
* 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 "exams.h"
+#include "ginac.h"
+using namespace GiNaC;
+
+#include <iostream>
+using namespace std;
static symbol x("x");
static unsigned check_series(const ex &e, const ex &point, const ex &d, int order = 8)
{
ex es = e.series(x==point, order);
- ex ep = ex_to_pseries(es).convert_to_poly();
- if (!(ep - d).is_zero()) {
+ ex ep = ex_to<pseries>(es).convert_to_poly();
+ if (!(ep - d).expand().is_zero()) {
clog << "series expansion of " << e << " at " << point
- << " erroneously returned " << ep << " (instead of " << d
- << ")" << endl;
- (ep-d).printtree(clog);
+ << " erroneously returned " << ep << " (instead of " << d
+ << ")" << endl;
+ clog << tree << (ep-d) << dflt;
return 1;
}
return 0;
}
// Series expansion
-static unsigned exam_series1(void)
+static unsigned exam_series1()
{
+ using GiNaC::log;
+
+ symbol a("a");
+ symbol b("b");
unsigned result = 0;
ex e, d;
+ e = pow(a+b, x);
+ d = 1 + Order(pow(x, 1));
+ result += check_series(e, 0, d, 1);
+
e = sin(x);
d = x - pow(x, 3) / 6 + pow(x, 5) / 120 - pow(x, 7) / 5040 + Order(pow(x, 8));
result += check_series(e, 0, d);
result += check_series(e, 1, d);
e = pow(x + pow(x, 3), -1);
- d = pow(x, -1) - x + pow(x, 3) - pow(x, 5) + Order(pow(x, 7));
+ d = pow(x, -1) - x + pow(x, 3) - pow(x, 5) + pow(x, 7) + Order(pow(x, 8));
result += check_series(e, 0, d);
e = pow(pow(x, 2) + pow(x, 4), -1);
- d = pow(x, -2) - 1 + pow(x, 2) - pow(x, 4) + Order(pow(x, 6));
+ d = pow(x, -2) - 1 + pow(x, 2) - pow(x, 4) + pow(x, 6) + Order(pow(x, 8));
result += check_series(e, 0, d);
e = pow(sin(x), -2);
- d = pow(x, -2) + numeric(1,3) + pow(x, 2) / 15 + pow(x, 4) * 2/189 + Order(pow(x, 5));
+ d = pow(x, -2) + numeric(1,3) + pow(x, 2) / 15 + pow(x, 4) * 2/189 + pow(x, 6) / 675 + Order(pow(x, 8));
result += check_series(e, 0, d);
e = sin(x) / cos(x);
result += check_series(e, 0, d);
e = cos(x) / sin(x);
- d = pow(x, -1) - x / 3 - pow(x, 3) / 45 - pow(x, 5) * 2/945 + Order(pow(x, 6));
+ d = pow(x, -1) - x / 3 - pow(x, 3) / 45 - pow(x, 5) * 2/945 - pow(x, 7) / 4725 + Order(pow(x, 8));
result += check_series(e, 0, d);
e = pow(numeric(2), x);
d = 1 + t + pow(t, 2) / 2 + pow(t, 3) / 6 + pow(t, 4) / 24 + pow(t, 5) / 120 + pow(t, 6) / 720 + pow(t, 7) / 5040 + Order(pow(x, 8));
result += check_series(e, 0, d.expand());
+ e = log(x);
+ d = e;
+ result += check_series(e, 0, d, 1);
+ result += check_series(e, 0, d, 2);
+
+ e = pow(x, 8) * pow(pow(x,3)+ pow(x + pow(x,3), 2), -2);
+ d = pow(x, 4) - 2*pow(x, 5) + Order(pow(x, 6));
+ result += check_series(e, 0, d, 6);
+
+ e = cos(x) * pow(sin(x)*(pow(x, 5) + 4 * pow(x, 2)), -3);
+ d = pow(x, -9) / 64 - 3 * pow(x, -6) / 256 - pow(x, -5) / 960 + 535 * pow(x, -3) / 96768
+ + pow(x, -2) / 1280 - pow(x, -1) / 14400 - numeric(283, 129024) - 2143 * x / 5322240
+ + Order(pow(x, 2));
+ result += check_series(e, 0, d, 2);
+
+ e = sqrt(1+x*x) * sqrt(1+2*x*x);
+ d = 1 + Order(pow(x, 2));
+ result += check_series(e, 0, d, 2);
+
+ e = pow(x, 4) * sin(a) + pow(x, 2);
+ d = pow(x, 2) + Order(pow(x, 3));
+ result += check_series(e, 0, d, 3);
+
+ e = log(a*x + b*x*x*log(x));
+ d = log(a*x) + b/a*log(x)*x - pow(b/a, 2)/2*pow(log(x)*x, 2) + Order(pow(x, 3));
+ result += check_series(e, 0, d, 3);
+
+ e = pow((x+a), b);
+ d = pow(a, b) + (pow(a, b)*b/a)*x + (pow(a, b)*b*b/a/a/2 - pow(a, b)*b/a/a/2)*pow(x, 2) + Order(pow(x, 3));
+ result += check_series(e, 0, d, 3);
+
+ e = a * (1 / (x * sin(x)) - sin(x) / x);
+ d = a * pow(x, -2) + Order(pow(x, -1));
+ result += check_series(e, 0, d, -1);
+
return result;
}
// Series addition
-static unsigned exam_series2(void)
+static unsigned exam_series2()
{
unsigned result = 0;
ex e, d;
e = pow(sin(x), -1).series(x==0, 8) + pow(sin(-x), -1).series(x==0, 12);
- d = Order(pow(x, 6));
+ d = Order(pow(x, 8));
result += check_series(e, 0, d);
return result;
}
// Series multiplication
-static unsigned exam_series3(void)
+static unsigned exam_series3()
{
unsigned result = 0;
ex e, d;
return result;
}
+// Series exponentiation
+static unsigned exam_series4()
+{
+ using GiNaC::tgamma;
+ unsigned result = 0;
+ ex e, d;
+
+ e = pow((2*cos(x)).series(x==0, 5), 2).series(x==0, 5);
+ d = 4 - 4*pow(x, 2) + 4*pow(x, 4)/3 + Order(pow(x, 5));
+ result += check_series(e, 0, d);
+
+ e = pow(tgamma(x), 2).series(x==0, 2);
+ d = pow(x,-2) - 2*Euler/x + (pow(Pi,2)/6+2*pow(Euler,2))
+ + x*(-4*pow(Euler, 3)/3 -pow(Pi,2)*Euler/3 - 2*zeta(3)/3) + Order(pow(x, 2));
+ result += check_series(e, 0, d);
+
+ return result;
+}
+
// Order term handling
-static unsigned exam_series4(void)
+static unsigned exam_series5()
{
unsigned result = 0;
ex e, d;
}
// Series expansion of tgamma(-1)
-static unsigned exam_series5(void)
+static unsigned exam_series6()
{
+ using GiNaC::tgamma;
ex e = tgamma(2*x);
ex d = pow(x+1,-1)*numeric(1,4) +
- pow(x+1,0)*(numeric(3,4) -
- numeric(1,2)*Euler) +
- pow(x+1,1)*(numeric(7,4) -
- numeric(3,2)*Euler +
- numeric(1,2)*pow(Euler,2) +
- numeric(1,12)*pow(Pi,2)) +
- pow(x+1,2)*(numeric(15,4) -
- numeric(7,2)*Euler -
- numeric(1,3)*pow(Euler,3) +
- numeric(1,4)*pow(Pi,2) +
- numeric(3,2)*pow(Euler,2) -
- numeric(1,6)*pow(Pi,2)*Euler -
- numeric(2,3)*zeta(3)) +
- pow(x+1,3)*(numeric(31,4) - pow(Euler,3) -
- numeric(15,2)*Euler +
- numeric(1,6)*pow(Euler,4) +
- numeric(7,2)*pow(Euler,2) +
- numeric(7,12)*pow(Pi,2) -
- numeric(1,2)*pow(Pi,2)*Euler -
- numeric(2)*zeta(3) +
- numeric(1,6)*pow(Euler,2)*pow(Pi,2) +
- numeric(1,40)*pow(Pi,4) +
- numeric(4,3)*zeta(3)*Euler) +
- Order(pow(x+1,4));
+ pow(x+1,0)*(numeric(3,4) -
+ numeric(1,2)*Euler) +
+ pow(x+1,1)*(numeric(7,4) -
+ numeric(3,2)*Euler +
+ numeric(1,2)*pow(Euler,2) +
+ numeric(1,12)*pow(Pi,2)) +
+ pow(x+1,2)*(numeric(15,4) -
+ numeric(7,2)*Euler -
+ numeric(1,3)*pow(Euler,3) +
+ numeric(1,4)*pow(Pi,2) +
+ numeric(3,2)*pow(Euler,2) -
+ numeric(1,6)*pow(Pi,2)*Euler -
+ numeric(2,3)*zeta(3)) +
+ pow(x+1,3)*(numeric(31,4) - pow(Euler,3) -
+ numeric(15,2)*Euler +
+ numeric(1,6)*pow(Euler,4) +
+ numeric(7,2)*pow(Euler,2) +
+ numeric(7,12)*pow(Pi,2) -
+ numeric(1,2)*pow(Pi,2)*Euler -
+ numeric(2)*zeta(3) +
+ numeric(1,6)*pow(Euler,2)*pow(Pi,2) +
+ numeric(1,40)*pow(Pi,4) +
+ numeric(4,3)*zeta(3)*Euler) +
+ Order(pow(x+1,4));
return check_series(e, -1, d, 4);
}
// Series expansion of tan(x==Pi/2)
-static unsigned exam_series6(void)
+static unsigned exam_series7()
{
ex e = tan(x*Pi/2);
ex d = pow(x-1,-1)/Pi*(-2) + pow(x-1,1)*Pi/6 + pow(x-1,3)*pow(Pi,3)/360
- +pow(x-1,5)*pow(Pi,5)/15120 + pow(x-1,7)*pow(Pi,7)/604800
- +Order(pow(x-1,8));
- return check_series(e,1,d,8);
+ +pow(x-1,5)*pow(Pi,5)/15120 + pow(x-1,7)*pow(Pi,7)/604800
+ +Order(pow(x-1,9));
+ return check_series(e,1,d,9);
}
// Series expansion of log(sin(x==0))
-static unsigned exam_series7(void)
+static unsigned exam_series8()
{
ex e = log(sin(x));
- ex d = log(x) - pow(x,2)/6 - pow(x,4)/180 - pow(x,6)/2835
- +Order(pow(x,8));
- return check_series(e,0,d,8);
+ ex d = log(x) - pow(x,2)/6 - pow(x,4)/180 - pow(x,6)/2835 - pow(x,8)/37800 + Order(pow(x,9));
+ return check_series(e,0,d,9);
}
// Series expansion of Li2(sin(x==0))
-static unsigned exam_series8(void)
+static unsigned exam_series9()
{
ex e = Li2(sin(x));
ex d = x + pow(x,2)/4 - pow(x,3)/18 - pow(x,4)/48
- - 13*pow(x,5)/1800 - pow(x,6)/360 - 23*pow(x,7)/21168
- + Order(pow(x,8));
+ - 13*pow(x,5)/1800 - pow(x,6)/360 - 23*pow(x,7)/21168
+ + Order(pow(x,8));
return check_series(e,0,d,8);
}
// Series expansion of Li2((x==2)^2), caring about branch-cut
-static unsigned exam_series9(void)
+static unsigned exam_series10()
{
+ using GiNaC::log;
+
ex e = Li2(pow(x,2));
ex d = Li2(4) + (-log(3) + I*Pi*csgn(I-I*pow(x,2))) * (x-2)
- + (numeric(-2,3) + log(3)/4 - I*Pi/4*csgn(I-I*pow(x,2))) * pow(x-2,2)
- + (numeric(11,27) - log(3)/12 + I*Pi/12*csgn(I-I*pow(x,2))) * pow(x-2,3)
- + (numeric(-155,648) + log(3)/32 - I*Pi/32*csgn(I-I*pow(x,2))) * pow(x-2,4)
- + Order(pow(x-2,5));
+ + (numeric(-2,3) + log(3)/4 - I*Pi/4*csgn(I-I*pow(x,2))) * pow(x-2,2)
+ + (numeric(11,27) - log(3)/12 + I*Pi/12*csgn(I-I*pow(x,2))) * pow(x-2,3)
+ + (numeric(-155,648) + log(3)/32 - I*Pi/32*csgn(I-I*pow(x,2))) * pow(x-2,4)
+ + Order(pow(x-2,5));
return check_series(e,2,d,5);
}
-unsigned exam_pseries(void)
+// Series expansion of logarithms around branch points
+static unsigned exam_series11()
+{
+ using GiNaC::log;
+
+ unsigned result = 0;
+ ex e, d;
+ symbol a("a");
+
+ e = log(x);
+ d = log(x);
+ result += check_series(e,0,d,5);
+
+ e = log(3/x);
+ d = log(3)-log(x);
+ result += check_series(e,0,d,5);
+
+ e = log(3*pow(x,2));
+ d = log(3)+2*log(x);
+ result += check_series(e,0,d,5);
+
+ // These ones must not be expanded because it would result in a branch cut
+ // running in the wrong direction. (Other systems tend to get this wrong.)
+ e = log(-x);
+ d = e;
+ result += check_series(e,0,d,5);
+
+ e = log(I*(x-123));
+ d = e;
+ result += check_series(e,123,d,5);
+
+ e = log(a*x);
+ d = e; // we don't know anything about a!
+ result += check_series(e,0,d,5);
+
+ e = log((1-x)/x);
+ d = log(1-x) - (x-1) + pow(x-1,2)/2 - pow(x-1,3)/3 + pow(x-1,4)/4 + Order(pow(x-1,5));
+ result += check_series(e,1,d,5);
+
+ return result;
+}
+
+// Series expansion of other functions around branch points
+static unsigned exam_series12()
+{
+ using GiNaC::log;
+ using GiNaC::atanh;
+
+ unsigned result = 0;
+ ex e, d;
+
+ // NB: Mma and Maple give different results, but they agree if one
+ // takes into account that by assumption |x|<1.
+ e = atan(x);
+ d = (I*log(2)/2-I*log(1+I*x)/2) + (x-I)/4 + I*pow(x-I,2)/16 + Order(pow(x-I,3));
+ result += check_series(e,I,d,3);
+
+ // NB: here, at -I, Mathematica disagrees, but it is wrong -- they
+ // pick up a complex phase by incorrectly expanding logarithms.
+ e = atan(x);
+ d = (-I*log(2)/2+I*log(1-I*x)/2) + (x+I)/4 - I*pow(x+I,2)/16 + Order(pow(x+I,3));
+ result += check_series(e,-I,d,3);
+
+ // This is basically the same as above, the branch point is at +/-1:
+ e = atanh(x);
+ d = (-log(2)/2+log(x+1)/2) + (x+1)/4 + pow(x+1,2)/16 + Order(pow(x+1,3));
+ result += check_series(e,-1,d,3);
+
+ return result;
+}
+
+// Test of the patch of Stefan Weinzierl that prevents an infinite loop if
+// a factor in a product is a complicated way of writing zero.
+static unsigned exam_series13()
+{
+ unsigned result = 0;
+
+ ex e = (new mul(pow(2,x), (1/x*(-(1+x)/(1-x)) + (1+x)/x/(1-x)))
+ )->setflag(status_flags::evaluated);
+ ex d = Order(x);
+ result += check_series(e,0,d,1);
+
+ return result;
+}
+
+// Test if (1+x)^(1/x) can be expanded.
+static unsigned exam_series14()
+{
+ unsigned result = 0;
+
+ ex e = pow(1+x, sin(x)/x);
+ ex d = 1 + x - pow(x,3)/6 + Order(pow(x,4));
+ try {
+ result += check_series(e,0,d,4);
+ } catch (const pole_error& err) {
+ clog << "series expansion of " << e << " at 0 raised an exception." << endl;
+ ++result;
+ }
+
+ return result;
+}
+
+unsigned exam_pseries()
{
unsigned result = 0;
cout << "examining series expansion" << flush;
- clog << "----------series expansion:" << endl;
result += exam_series1(); cout << '.' << flush;
result += exam_series2(); cout << '.' << flush;
result += exam_series7(); cout << '.' << flush;
result += exam_series8(); cout << '.' << flush;
result += exam_series9(); cout << '.' << flush;
+ result += exam_series10(); cout << '.' << flush;
+ result += exam_series11(); cout << '.' << flush;
+ result += exam_series12(); cout << '.' << flush;
+ result += exam_series13(); cout << '.' << flush;
+ result += exam_series14(); cout << '.' << flush;
- if (!result) {
- cout << " passed " << endl;
- clog << "(no output)" << endl;
- } else {
- cout << " failed " << endl;
- }
return result;
}
+
+int main(int argc, char** argv)
+{
+ return exam_pseries();
+}
git://www.ginac.de / ginac.git / blobdiff