* Implementation of GiNaC's initially known functions. */
/*
- * GiNaC Copyright (C) 1999-2010 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
#include "ex.h"
#include "constant.h"
#include "lst.h"
+#include "fderivative.h"
#include "matrix.h"
#include "mul.h"
#include "power.h"
return arg;
}
+// If x is real then U.diff(x)-I*V.diff(x) represents both conjugate(U+I*V).diff(x)
+// and conjugate((U+I*V).diff(x))
+static ex conjugate_expl_derivative(const ex & arg, const symbol & s)
+{
+ if (s.info(info_flags::real))
+ return conjugate(arg.diff(s));
+ else {
+ exvector vec_arg;
+ vec_arg.push_back(arg);
+ return fderivative(ex_to<function>(conjugate(arg)).get_serial(),0,vec_arg).hold()*arg.diff(s);
+ }
+}
+
static ex conjugate_real_part(const ex & arg)
{
return arg.real_part();
return -arg.imag_part();
}
+static bool func_arg_info(const ex & arg, unsigned inf)
+{
+ // for some functions we can return the info() of its argument
+ // (think of conjugate())
+ switch (inf) {
+ case info_flags::polynomial:
+ case info_flags::integer_polynomial:
+ case info_flags::cinteger_polynomial:
+ case info_flags::rational_polynomial:
+ case info_flags::real:
+ case info_flags::rational:
+ case info_flags::integer:
+ case info_flags::crational:
+ case info_flags::cinteger:
+ case info_flags::even:
+ case info_flags::odd:
+ case info_flags::prime:
+ case info_flags::crational_polynomial:
+ case info_flags::rational_function:
+ case info_flags::positive:
+ case info_flags::negative:
+ case info_flags::nonnegative:
+ case info_flags::posint:
+ case info_flags::negint:
+ case info_flags::nonnegint:
+ case info_flags::has_indices:
+ return arg.info(inf);
+ }
+ return false;
+}
+
+static bool conjugate_info(const ex & arg, unsigned inf)
+{
+ return func_arg_info(arg, inf);
+}
+
REGISTER_FUNCTION(conjugate_function, eval_func(conjugate_eval).
evalf_func(conjugate_evalf).
+ expl_derivative_func(conjugate_expl_derivative).
+ info_func(conjugate_info).
print_func<print_latex>(conjugate_print_latex).
conjugate_func(conjugate_conjugate).
real_part_func(conjugate_real_part).
return 0;
}
+// If x is real then Re(e).diff(x) is equal to Re(e.diff(x))
+static ex real_part_expl_derivative(const ex & arg, const symbol & s)
+{
+ if (s.info(info_flags::real))
+ return real_part_function(arg.diff(s));
+ else {
+ exvector vec_arg;
+ vec_arg.push_back(arg);
+ return fderivative(ex_to<function>(real_part(arg)).get_serial(),0,vec_arg).hold()*arg.diff(s);
+ }
+}
+
REGISTER_FUNCTION(real_part_function, eval_func(real_part_eval).
evalf_func(real_part_evalf).
+ expl_derivative_func(real_part_expl_derivative).
print_func<print_latex>(real_part_print_latex).
conjugate_func(real_part_conjugate).
real_part_func(real_part_real_part).
return 0;
}
+// If x is real then Im(e).diff(x) is equal to Im(e.diff(x))
+static ex imag_part_expl_derivative(const ex & arg, const symbol & s)
+{
+ if (s.info(info_flags::real))
+ return imag_part_function(arg.diff(s));
+ else {
+ exvector vec_arg;
+ vec_arg.push_back(arg);
+ return fderivative(ex_to<function>(imag_part(arg)).get_serial(),0,vec_arg).hold()*arg.diff(s);
+ }
+}
+
REGISTER_FUNCTION(imag_part_function, eval_func(imag_part_eval).
evalf_func(imag_part_evalf).
+ expl_derivative_func(imag_part_expl_derivative).
print_func<print_latex>(imag_part_print_latex).
conjugate_func(imag_part_conjugate).
real_part_func(imag_part_real_part).
if (arg.info(info_flags::nonnegative))
return arg;
+ if (arg.info(info_flags::negative) || (-arg).info(info_flags::nonnegative))
+ return -arg;
+
if (is_ex_the_function(arg, abs))
return arg;
+ if (is_ex_the_function(arg, exp))
+ return exp(arg.op(0).real_part());
+
+ if (is_exactly_a<power>(arg)) {
+ const ex& base = arg.op(0);
+ const ex& exponent = arg.op(1);
+ if (base.info(info_flags::positive) || exponent.info(info_flags::real))
+ return pow(abs(base), exponent.real_part());
+ }
+
+ if (is_ex_the_function(arg, conjugate_function))
+ return abs(arg.op(0));
+
+ if (is_ex_the_function(arg, step))
+ return arg;
+
return abs(arg).hold();
}
+static ex abs_expand(const ex & arg, unsigned options)
+{
+ if ((options & expand_options::expand_transcendental)
+ && is_exactly_a<mul>(arg)) {
+ exvector prodseq;
+ prodseq.reserve(arg.nops());
+ for (const_iterator i = arg.begin(); i != arg.end(); ++i) {
+ if (options & expand_options::expand_function_args)
+ prodseq.push_back(abs(i->expand(options)));
+ else
+ prodseq.push_back(abs(*i));
+ }
+ return dynallocate<mul>(prodseq).setflag(status_flags::expanded);
+ }
+
+ if (options & expand_options::expand_function_args)
+ return abs(arg.expand(options)).hold();
+ else
+ return abs(arg).hold();
+}
+
+static ex abs_expl_derivative(const ex & arg, const symbol & s)
+{
+ ex diff_arg = arg.diff(s);
+ return (diff_arg*arg.conjugate()+arg*diff_arg.conjugate())/2/abs(arg);
+}
+
static void abs_print_latex(const ex & arg, const print_context & c)
{
c.s << "{|"; arg.print(c); c.s << "|}";
static ex abs_conjugate(const ex & arg)
{
- return abs(arg);
+ return abs(arg).hold();
}
static ex abs_real_part(const ex & arg)
static ex abs_power(const ex & arg, const ex & exp)
{
- if (arg.is_equal(arg.conjugate()) && is_a<numeric>(exp) && ex_to<numeric>(exp).is_even())
- return power(arg, exp);
- else
+ if ((is_a<numeric>(exp) && ex_to<numeric>(exp).is_even()) || exp.info(info_flags::even)) {
+ if (arg.info(info_flags::real) || arg.is_equal(arg.conjugate()))
+ return pow(arg, exp);
+ else
+ return pow(arg, exp/2) * pow(arg.conjugate(), exp/2);
+ } else
return power(abs(arg), exp).hold();
}
+bool abs_info(const ex & arg, unsigned inf)
+{
+ switch (inf) {
+ case info_flags::integer:
+ case info_flags::even:
+ case info_flags::odd:
+ case info_flags::prime:
+ return arg.info(inf);
+ case info_flags::nonnegint:
+ return arg.info(info_flags::integer);
+ case info_flags::nonnegative:
+ case info_flags::real:
+ return true;
+ case info_flags::negative:
+ return false;
+ case info_flags::positive:
+ return arg.info(info_flags::positive) || arg.info(info_flags::negative);
+ case info_flags::has_indices: {
+ if (arg.info(info_flags::has_indices))
+ return true;
+ else
+ return false;
+ }
+ }
+ return false;
+}
+
REGISTER_FUNCTION(abs, eval_func(abs_eval).
evalf_func(abs_evalf).
+ expand_func(abs_expand).
+ expl_derivative_func(abs_expl_derivative).
+ info_func(abs_info).
print_func<print_latex>(abs_print_latex).
print_func<print_csrc_float>(abs_print_csrc_float).
print_func<print_csrc_double>(abs_print_csrc_float).
&& !(options & series_options::suppress_branchcut))
throw (std::domain_error("step_series(): on imaginary axis"));
- epvector seq;
- seq.push_back(expair(step(arg_pt), _ex0));
- return pseries(rel,seq);
+ epvector seq { expair(step(arg_pt), _ex0) };
+ return pseries(rel, std::move(seq));
}
static ex step_conjugate(const ex& arg)
&& !(options & series_options::suppress_branchcut))
throw (std::domain_error("csgn_series(): on imaginary axis"));
- epvector seq;
- seq.push_back(expair(csgn(arg_pt), _ex0));
- return pseries(rel,seq);
+ epvector seq { expair(csgn(arg_pt), _ex0) };
+ return pseries(rel, std::move(seq));
}
static ex csgn_conjugate(const ex& arg)
{
if (is_a<numeric>(exp) && exp.info(info_flags::positive) && ex_to<numeric>(exp).is_integer()) {
if (ex_to<numeric>(exp).is_odd())
- return csgn(arg);
+ return csgn(arg).hold();
else
return power(csgn(arg), _ex2).hold();
} else
(y_pt.info(info_flags::numeric) && y_pt.info(info_flags::negative)) ||
((x_pt*y_pt).info(info_flags::numeric) && (x_pt*y_pt).info(info_flags::negative)))
throw (std::domain_error("eta_series(): on discontinuity"));
- epvector seq;
- seq.push_back(expair(eta(x_pt,y_pt), _ex0));
- return pseries(rel,seq);
+ epvector seq { expair(eta(x_pt,y_pt), _ex0) };
+ return pseries(rel, std::move(seq));
}
static ex eta_conjugate(const ex & x, const ex & y)
{
- return -eta(x, y);
+ return -eta(x, y).hold();
}
static ex eta_real_part(const ex & x, const ex & y)
// substitute the argument's series expansion
ser = ser.subs(s==x.series(rel, order), subs_options::no_pattern);
// maybe that was terminating, so add a proper order term
- epvector nseq;
- nseq.push_back(expair(Order(_ex1), order));
- ser += pseries(rel, nseq);
+ epvector nseq { expair(Order(_ex1), order) };
+ ser += pseries(rel, std::move(nseq));
// reexpanding it will collapse the series again
return ser.series(rel, order);
// NB: Of course, this still does not allow us to compute anything
// substitute the argument's series expansion
ser = ser.subs(s==x.series(rel, order), subs_options::no_pattern);
// maybe that was terminating, so add a proper order term
- epvector nseq;
- nseq.push_back(expair(Order(_ex1), order));
- ser += pseries(rel, nseq);
+ epvector nseq { expair(Order(_ex1), order) };
+ ser += pseries(rel, std::move(nseq));
// reexpanding it will collapse the series again
return ser.series(rel, order);
}
seq.push_back(expair((replarg.op(i)/power(s-foo,i)).series(foo==point,1,options).op(0).subs(foo==s, subs_options::no_pattern),i));
// append an order term:
seq.push_back(expair(Order(_ex1), replarg.nops()-1));
- return pseries(rel, seq);
+ return pseries(rel, std::move(seq));
}
}
// all other cases should be safe, by now:
// conjugate(Li2(x))==Li2(conjugate(x)) unless on the branch cuts which
// run along the positive real axis beginning at 1.
if (x.info(info_flags::negative)) {
- return Li2(x);
+ return Li2(x).hold();
}
if (is_exactly_a<numeric>(x) &&
(!x.imag_part().is_zero() || x < *_num1_p)) {
if (n.info(info_flags::numeric)) {
// zetaderiv(0,x) -> zeta(x)
if (n.is_zero())
- return zeta(x);
+ return zeta(x).hold();
}
return zetaderiv(n, x).hold();
return binomial(x, y).hold();
}
-// At the moment the numeric evaluation of a binomail function always
+// At the moment the numeric evaluation of a binomial function always
// gives a real number, but if this would be implemented using the gamma
// function, also complex conjugation should be changed (or rather, deleted).
static ex binomial_conjugate(const ex & x, const ex & y)
static ex Order_series(const ex & x, const relational & r, int order, unsigned options)
{
// Just wrap the function into a pseries object
- epvector new_seq;
GINAC_ASSERT(is_a<symbol>(r.lhs()));
const symbol &s = ex_to<symbol>(r.lhs());
- new_seq.push_back(expair(Order(_ex1), numeric(std::min(x.ldegree(s), order))));
- return pseries(r, new_seq);
+ epvector new_seq { expair(Order(_ex1), numeric(std::min(x.ldegree(s), order))) };
+ return pseries(r, std::move(new_seq));
}
static ex Order_conjugate(const ex & x)
return Order(x).hold();
}
-// Differentiation is handled in function::derivative because of its special requirements
+static ex Order_expl_derivative(const ex & arg, const symbol & s)
+{
+ return Order(arg.diff(s));
+}
REGISTER_FUNCTION(Order, eval_func(Order_eval).
series_func(Order_series).
latex_name("\\mathcal{O}").
+ expl_derivative_func(Order_expl_derivative).
conjugate_func(Order_conjugate).
real_part_func(Order_real_part).
imag_part_func(Order_imag_part));
// Solve linear system
//////////
+class symbolset {
+ exset s;
+ void insert_symbols(const ex &e)
+ {
+ if (is_a<symbol>(e)) {
+ s.insert(e);
+ } else {
+ for (const ex &sube : e) {
+ insert_symbols(sube);
+ }
+ }
+ }
+public:
+ explicit symbolset(const ex &e)
+ {
+ insert_symbols(e);
+ }
+ bool has(const ex &e) const
+ {
+ return s.find(e) != s.end();
+ }
+};
+
ex lsolve(const ex &eqns, const ex &symbols, unsigned options)
{
// solve a system of linear equations
if (eqns.info(info_flags::relation_equal)) {
if (!symbols.info(info_flags::symbol))
throw(std::invalid_argument("lsolve(): 2nd argument must be a symbol"));
- const ex sol = lsolve(lst(eqns),lst(symbols));
+ const ex sol = lsolve(lst{eqns}, lst{symbols});
GINAC_ASSERT(sol.nops()==1);
GINAC_ASSERT(is_exactly_a<relational>(sol.op(0)));
}
// syntax checks
- if (!eqns.info(info_flags::list)) {
- throw(std::invalid_argument("lsolve(): 1st argument must be a list or an equation"));
+ if (!(eqns.info(info_flags::list) || eqns.info(info_flags::exprseq))) {
+ throw(std::invalid_argument("lsolve(): 1st argument must be a list, a sequence, or an equation"));
}
for (size_t i=0; i<eqns.nops(); i++) {
if (!eqns.op(i).info(info_flags::relation_equal)) {
throw(std::invalid_argument("lsolve(): 1st argument must be a list of equations"));
}
}
- if (!symbols.info(info_flags::list)) {
- throw(std::invalid_argument("lsolve(): 2nd argument must be a list or a symbol"));
+ if (!(symbols.info(info_flags::list) || symbols.info(info_flags::exprseq))) {
+ throw(std::invalid_argument("lsolve(): 2nd argument must be a list, a sequence, or a symbol"));
}
for (size_t i=0; i<symbols.nops(); i++) {
if (!symbols.op(i).info(info_flags::symbol)) {
- throw(std::invalid_argument("lsolve(): 2nd argument must be a list of symbols"));
+ throw(std::invalid_argument("lsolve(): 2nd argument must be a list or a sequence of symbols"));
}
}
for (size_t r=0; r<eqns.nops(); r++) {
const ex eq = eqns.op(r).op(0)-eqns.op(r).op(1); // lhs-rhs==0
+ const symbolset syms(eq);
ex linpart = eq;
for (size_t c=0; c<symbols.nops(); c++) {
+ if (!syms.has(symbols.op(c)))
+ continue;
const ex co = eq.coeff(ex_to<symbol>(symbols.op(c)),1);
linpart -= co*symbols.op(c);
sys(r,c) = co;
}
// test if system is linear and fill vars matrix
+ const symbolset sys_syms(sys);
+ const symbolset rhs_syms(rhs);
for (size_t i=0; i<symbols.nops(); i++) {
vars(i,0) = symbols.op(i);
- if (sys.has(symbols.op(i)))
+ if (sys_syms.has(symbols.op(i)))
throw(std::logic_error("lsolve: system is not linear"));
- if (rhs.has(symbols.op(i)))
+ if (rhs_syms.has(symbols.op(i)))
throw(std::logic_error("lsolve: system is not linear"));
}
} catch (const std::runtime_error & e) {
// Probably singular matrix or otherwise overdetermined system:
// It is consistent to return an empty list
- return lst();
+ return lst{};
}
GINAC_ASSERT(solution.cols()==1);
GINAC_ASSERT(solution.rows()==symbols.nops());
- // return list of equations of the form lst(var1==sol1,var2==sol2,...)
+ // return list of equations of the form lst{var1==sol1,var2==sol2,...}
lst sollist;
for (size_t i=0; i<symbols.nops(); i++)
sollist.append(symbols.op(i)==solution(i,0));
do {
xxprev = xx[side];
fxprev = fx[side];
- xx[side] += ex_to<numeric>(ff.subs(x==xx[side]).evalf());
- fx[side] = ex_to<numeric>(f.subs(x==xx[side]).evalf());
- if ((side==0 && xx[0]<xxprev) || (side==1 && xx[1]>xxprev) || xx[0]>xx[1]) {
+ ex dx_ = ff.subs(x == xx[side]).evalf();
+ if (!is_a<numeric>(dx_))
+ throw std::runtime_error("fsolve(): function derivative does not evaluate numerically");
+ xx[side] += ex_to<numeric>(dx_);
+ // Now check if Newton-Raphson method shot out of the interval
+ bool bad_shot = (side == 0 && xx[0] < xxprev) ||
+ (side == 1 && xx[1] > xxprev) || xx[0] > xx[1];
+ if (!bad_shot) {
+ // Compute f(x) only if new x is inside the interval.
+ // The function might be difficult to compute numerically
+ // or even ill defined outside the interval. Also it's
+ // a small optimization.
+ ex f_x = f.subs(x == xx[side]).evalf();
+ if (!is_a<numeric>(f_x))
+ throw std::runtime_error("fsolve(): function does not evaluate numerically");
+ fx[side] = ex_to<numeric>(f_x);
+ }
+ if (bad_shot) {
// Oops, Newton-Raphson method shot out of the interval.
// Restore, and try again with the other side instead!
xx[side] = xxprev;
side = !side;
xxprev = xx[side];
fxprev = fx[side];
- xx[side] += ex_to<numeric>(ff.subs(x==xx[side]).evalf());
- fx[side] = ex_to<numeric>(f.subs(x==xx[side]).evalf());
+
+ ex dx_ = ff.subs(x == xx[side]).evalf();
+ if (!is_a<numeric>(dx_))
+ throw std::runtime_error("fsolve(): function derivative does not evaluate numerically [2]");
+ xx[side] += ex_to<numeric>(dx_);
+
+ ex f_x = f.subs(x==xx[side]).evalf();
+ if (!is_a<numeric>(f_x))
+ throw std::runtime_error("fsolve(): function does not evaluate numerically [2]");
+ fx[side] = ex_to<numeric>(f_x);
}
if ((fx[side]<0 && fx[!side]<0) || (fx[side]>0 && fx[!side]>0)) {
// Oops, the root isn't bracketed any more.
// determined by the secant between the values xx[0] and xx[1].
// Don't set the secant_weight to one because that could disturb
// the convergence in some corner cases!
- static const double secant_weight = 0.984375; // == 63/64 < 1
+ constexpr double secant_weight = 0.984375; // == 63/64 < 1
numeric xxmid = (1-secant_weight)*0.5*(xx[0]+xx[1])
+ secant_weight*(xx[0]+fx[0]*(xx[0]-xx[1])/(fx[1]-fx[0]));
- numeric fxmid = ex_to<numeric>(f.subs(x==xxmid).evalf());
+ ex fxmid_ = f.subs(x == xxmid).evalf();
+ if (!is_a<numeric>(fxmid_))
+ throw std::runtime_error("fsolve(): function does not evaluate numerically [3]");
+ numeric fxmid = ex_to<numeric>(fxmid_);
if (fxmid.is_zero()) {
// Luck strikes...
return xxmid;
git://www.ginac.de / ginac.git / blobdiff