3 * This file contains the interface to the underlying bignum package.
4 * Its most important design principle is to completely hide the inner
5 * working of that other package from the user of GiNaC. It must either
6 * provide implementation of arithmetic operators and numerical evaluation
7 * of special functions or implement the interface to the bignum package. */
10 * GiNaC Copyright (C) 1999-2002 Johannes Gutenberg University Mainz, Germany
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
37 #include "operators.h"
42 // CLN should pollute the global namespace as little as possible. Hence, we
43 // include most of it here and include only the part needed for properly
44 // declaring cln::cl_number in numeric.h. This can only be safely done in
45 // namespaced versions of CLN, i.e. version > 1.1.0. Also, we only need a
46 // subset of CLN, so we don't include the complete <cln/cln.h> but only the
48 #include <cln/output.h>
49 #include <cln/integer_io.h>
50 #include <cln/integer_ring.h>
51 #include <cln/rational_io.h>
52 #include <cln/rational_ring.h>
53 #include <cln/lfloat_class.h>
54 #include <cln/lfloat_io.h>
55 #include <cln/real_io.h>
56 #include <cln/real_ring.h>
57 #include <cln/complex_io.h>
58 #include <cln/complex_ring.h>
59 #include <cln/numtheory.h>
63 GINAC_IMPLEMENT_REGISTERED_CLASS(numeric, basic)
66 // default ctor, dtor, copy ctor, assignment operator and helpers
69 /** default ctor. Numerically it initializes to an integer zero. */
70 numeric::numeric() : basic(TINFO_numeric)
73 setflag(status_flags::evaluated | status_flags::expanded);
76 void numeric::copy(const numeric &other)
78 inherited::copy(other);
82 DEFAULT_DESTROY(numeric)
90 numeric::numeric(int i) : basic(TINFO_numeric)
92 // Not the whole int-range is available if we don't cast to long
93 // first. This is due to the behaviour of the cl_I-ctor, which
94 // emphasizes efficiency. However, if the integer is small enough
95 // we save space and dereferences by using an immediate type.
96 // (C.f. <cln/object.h>)
97 if (i < (1U<<cl_value_len-1))
100 value = cln::cl_I((long) i);
101 setflag(status_flags::evaluated | status_flags::expanded);
105 numeric::numeric(unsigned int i) : basic(TINFO_numeric)
107 // Not the whole uint-range is available if we don't cast to ulong
108 // first. This is due to the behaviour of the cl_I-ctor, which
109 // emphasizes efficiency. However, if the integer is small enough
110 // we save space and dereferences by using an immediate type.
111 // (C.f. <cln/object.h>)
112 if (i < (1U<<cl_value_len-1))
113 value = cln::cl_I(i);
115 value = cln::cl_I((unsigned long) i);
116 setflag(status_flags::evaluated | status_flags::expanded);
120 numeric::numeric(long i) : basic(TINFO_numeric)
122 value = cln::cl_I(i);
123 setflag(status_flags::evaluated | status_flags::expanded);
127 numeric::numeric(unsigned long i) : basic(TINFO_numeric)
129 value = cln::cl_I(i);
130 setflag(status_flags::evaluated | status_flags::expanded);
133 /** Ctor for rational numerics a/b.
135 * @exception overflow_error (division by zero) */
136 numeric::numeric(long numer, long denom) : basic(TINFO_numeric)
139 throw std::overflow_error("division by zero");
140 value = cln::cl_I(numer) / cln::cl_I(denom);
141 setflag(status_flags::evaluated | status_flags::expanded);
145 numeric::numeric(double d) : basic(TINFO_numeric)
147 // We really want to explicitly use the type cl_LF instead of the
148 // more general cl_F, since that would give us a cl_DF only which
149 // will not be promoted to cl_LF if overflow occurs:
150 value = cln::cl_float(d, cln::default_float_format);
151 setflag(status_flags::evaluated | status_flags::expanded);
155 /** ctor from C-style string. It also accepts complex numbers in GiNaC
156 * notation like "2+5*I". */
157 numeric::numeric(const char *s) : basic(TINFO_numeric)
159 cln::cl_N ctorval = 0;
160 // parse complex numbers (functional but not completely safe, unfortunately
161 // std::string does not understand regexpese):
162 // ss should represent a simple sum like 2+5*I
164 std::string::size_type delim;
166 // make this implementation safe by adding explicit sign
167 if (ss.at(0) != '+' && ss.at(0) != '-' && ss.at(0) != '#')
170 // We use 'E' as exponent marker in the output, but some people insist on
171 // writing 'e' at input, so let's substitute them right at the beginning:
172 while ((delim = ss.find("e"))!=std::string::npos)
173 ss.replace(delim,1,"E");
177 // chop ss into terms from left to right
179 bool imaginary = false;
180 delim = ss.find_first_of(std::string("+-"),1);
181 // Do we have an exponent marker like "31.415E-1"? If so, hop on!
182 if (delim!=std::string::npos && ss.at(delim-1)=='E')
183 delim = ss.find_first_of(std::string("+-"),delim+1);
184 term = ss.substr(0,delim);
185 if (delim!=std::string::npos)
186 ss = ss.substr(delim);
187 // is the term imaginary?
188 if (term.find("I")!=std::string::npos) {
190 term.erase(term.find("I"),1);
192 if (term.find("*")!=std::string::npos)
193 term.erase(term.find("*"),1);
194 // correct for trivial +/-I without explicit factor on I:
199 if (term.find('.')!=std::string::npos || term.find('E')!=std::string::npos) {
200 // CLN's short type cl_SF is not very useful within the GiNaC
201 // framework where we are mainly interested in the arbitrary
202 // precision type cl_LF. Hence we go straight to the construction
203 // of generic floats. In order to create them we have to convert
204 // our own floating point notation used for output and construction
205 // from char * to CLN's generic notation:
206 // 3.14 --> 3.14e0_<Digits>
207 // 31.4E-1 --> 31.4e-1_<Digits>
209 // No exponent marker? Let's add a trivial one.
210 if (term.find("E")==std::string::npos)
213 term = term.replace(term.find("E"),1,"e");
214 // append _<Digits> to term
215 term += "_" + ToString((unsigned)Digits);
216 // construct float using cln::cl_F(const char *) ctor.
218 ctorval = ctorval + cln::complex(cln::cl_I(0),cln::cl_F(term.c_str()));
220 ctorval = ctorval + cln::cl_F(term.c_str());
222 // this is not a floating point number...
224 ctorval = ctorval + cln::complex(cln::cl_I(0),cln::cl_R(term.c_str()));
226 ctorval = ctorval + cln::cl_R(term.c_str());
228 } while (delim != std::string::npos);
230 setflag(status_flags::evaluated | status_flags::expanded);
234 /** Ctor from CLN types. This is for the initiated user or internal use
236 numeric::numeric(const cln::cl_N &z) : basic(TINFO_numeric)
239 setflag(status_flags::evaluated | status_flags::expanded);
246 numeric::numeric(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst)
248 cln::cl_N ctorval = 0;
250 // Read number as string
252 if (n.find_string("number", str)) {
253 std::istringstream s(str);
254 cln::cl_idecoded_float re, im;
258 case 'R': // Integer-decoded real number
259 s >> re.sign >> re.mantissa >> re.exponent;
260 ctorval = re.sign * re.mantissa * cln::expt(cln::cl_float(2.0, cln::default_float_format), re.exponent);
262 case 'C': // Integer-decoded complex number
263 s >> re.sign >> re.mantissa >> re.exponent;
264 s >> im.sign >> im.mantissa >> im.exponent;
265 ctorval = cln::complex(re.sign * re.mantissa * cln::expt(cln::cl_float(2.0, cln::default_float_format), re.exponent),
266 im.sign * im.mantissa * cln::expt(cln::cl_float(2.0, cln::default_float_format), im.exponent));
268 default: // Ordinary number
275 setflag(status_flags::evaluated | status_flags::expanded);
278 void numeric::archive(archive_node &n) const
280 inherited::archive(n);
282 // Write number as string
283 std::ostringstream s;
284 if (this->is_crational())
285 s << cln::the<cln::cl_N>(value);
287 // Non-rational numbers are written in an integer-decoded format
288 // to preserve the precision
289 if (this->is_real()) {
290 cln::cl_idecoded_float re = cln::integer_decode_float(cln::the<cln::cl_F>(value));
292 s << re.sign << " " << re.mantissa << " " << re.exponent;
294 cln::cl_idecoded_float re = cln::integer_decode_float(cln::the<cln::cl_F>(cln::realpart(cln::the<cln::cl_N>(value))));
295 cln::cl_idecoded_float im = cln::integer_decode_float(cln::the<cln::cl_F>(cln::imagpart(cln::the<cln::cl_N>(value))));
297 s << re.sign << " " << re.mantissa << " " << re.exponent << " ";
298 s << im.sign << " " << im.mantissa << " " << im.exponent;
301 n.add_string("number", s.str());
304 DEFAULT_UNARCHIVE(numeric)
307 // functions overriding virtual functions from base classes
310 /** Helper function to print a real number in a nicer way than is CLN's
311 * default. Instead of printing 42.0L0 this just prints 42.0 to ostream os
312 * and instead of 3.99168L7 it prints 3.99168E7. This is fine in GiNaC as
313 * long as it only uses cl_LF and no other floating point types that we might
314 * want to visibly distinguish from cl_LF.
316 * @see numeric::print() */
317 static void print_real_number(const print_context & c, const cln::cl_R &x)
319 cln::cl_print_flags ourflags;
320 if (cln::instanceof(x, cln::cl_RA_ring)) {
321 // case 1: integer or rational
322 if (cln::instanceof(x, cln::cl_I_ring) ||
323 !is_a<print_latex>(c)) {
324 cln::print_real(c.s, ourflags, x);
325 } else { // rational output in LaTeX context
327 cln::print_real(c.s, ourflags, cln::numerator(cln::the<cln::cl_RA>(x)));
329 cln::print_real(c.s, ourflags, cln::denominator(cln::the<cln::cl_RA>(x)));
334 // make CLN believe this number has default_float_format, so it prints
335 // 'E' as exponent marker instead of 'L':
336 ourflags.default_float_format = cln::float_format(cln::the<cln::cl_F>(x));
337 cln::print_real(c.s, ourflags, x);
341 /** This method adds to the output so it blends more consistently together
342 * with the other routines and produces something compatible to ginsh input.
344 * @see print_real_number() */
345 void numeric::print(const print_context & c, unsigned level) const
347 if (is_a<print_tree>(c)) {
349 c.s << std::string(level, ' ') << cln::the<cln::cl_N>(value)
350 << " (" << class_name() << ")"
351 << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
354 } else if (is_a<print_csrc>(c)) {
356 std::ios::fmtflags oldflags = c.s.flags();
357 c.s.setf(std::ios::scientific);
358 if (this->is_rational() && !this->is_integer()) {
359 if (compare(_num0) > 0) {
361 if (is_a<print_csrc_cl_N>(c))
362 c.s << "cln::cl_F(\"" << numer().evalf() << "\")";
364 c.s << numer().to_double();
367 if (is_a<print_csrc_cl_N>(c))
368 c.s << "cln::cl_F(\"" << -numer().evalf() << "\")";
370 c.s << -numer().to_double();
373 if (is_a<print_csrc_cl_N>(c))
374 c.s << "cln::cl_F(\"" << denom().evalf() << "\")";
376 c.s << denom().to_double();
379 if (is_a<print_csrc_cl_N>(c))
380 c.s << "cln::cl_F(\"" << evalf() << "\")";
387 const std::string par_open = is_a<print_latex>(c) ? "{(" : "(";
388 const std::string par_close = is_a<print_latex>(c) ? ")}" : ")";
389 const std::string imag_sym = is_a<print_latex>(c) ? "i" : "I";
390 const std::string mul_sym = is_a<print_latex>(c) ? " " : "*";
391 const cln::cl_R r = cln::realpart(cln::the<cln::cl_N>(value));
392 const cln::cl_R i = cln::imagpart(cln::the<cln::cl_N>(value));
393 if (is_a<print_python_repr>(c))
394 c.s << class_name() << "('";
396 // case 1, real: x or -x
397 if ((precedence() <= level) && (!this->is_nonneg_integer())) {
399 print_real_number(c, r);
402 print_real_number(c, r);
406 // case 2, imaginary: y*I or -y*I
410 if (precedence()<=level)
413 c.s << "-" << imag_sym;
415 print_real_number(c, i);
416 c.s << mul_sym+imag_sym;
418 if (precedence()<=level)
422 // case 3, complex: x+y*I or x-y*I or -x+y*I or -x-y*I
423 if (precedence() <= level)
425 print_real_number(c, r);
430 print_real_number(c, i);
431 c.s << mul_sym+imag_sym;
438 print_real_number(c, i);
439 c.s << mul_sym+imag_sym;
442 if (precedence() <= level)
446 if (is_a<print_python_repr>(c))
451 bool numeric::info(unsigned inf) const
454 case info_flags::numeric:
455 case info_flags::polynomial:
456 case info_flags::rational_function:
458 case info_flags::real:
460 case info_flags::rational:
461 case info_flags::rational_polynomial:
462 return is_rational();
463 case info_flags::crational:
464 case info_flags::crational_polynomial:
465 return is_crational();
466 case info_flags::integer:
467 case info_flags::integer_polynomial:
469 case info_flags::cinteger:
470 case info_flags::cinteger_polynomial:
471 return is_cinteger();
472 case info_flags::positive:
473 return is_positive();
474 case info_flags::negative:
475 return is_negative();
476 case info_flags::nonnegative:
477 return !is_negative();
478 case info_flags::posint:
479 return is_pos_integer();
480 case info_flags::negint:
481 return is_integer() && is_negative();
482 case info_flags::nonnegint:
483 return is_nonneg_integer();
484 case info_flags::even:
486 case info_flags::odd:
488 case info_flags::prime:
490 case info_flags::algebraic:
496 int numeric::degree(const ex & s) const
501 int numeric::ldegree(const ex & s) const
506 ex numeric::coeff(const ex & s, int n) const
508 return n==0 ? *this : _ex0;
511 /** Disassemble real part and imaginary part to scan for the occurrence of a
512 * single number. Also handles the imaginary unit. It ignores the sign on
513 * both this and the argument, which may lead to what might appear as funny
514 * results: (2+I).has(-2) -> true. But this is consistent, since we also
515 * would like to have (-2+I).has(2) -> true and we want to think about the
516 * sign as a multiplicative factor. */
517 bool numeric::has(const ex &other) const
519 if (!is_exactly_a<numeric>(other))
521 const numeric &o = ex_to<numeric>(other);
522 if (this->is_equal(o) || this->is_equal(-o))
524 if (o.imag().is_zero()) // e.g. scan for 3 in -3*I
525 return (this->real().is_equal(o) || this->imag().is_equal(o) ||
526 this->real().is_equal(-o) || this->imag().is_equal(-o));
528 if (o.is_equal(I)) // e.g scan for I in 42*I
529 return !this->is_real();
530 if (o.real().is_zero()) // e.g. scan for 2*I in 2*I+1
531 return (this->real().has(o*I) || this->imag().has(o*I) ||
532 this->real().has(-o*I) || this->imag().has(-o*I));
538 /** Evaluation of numbers doesn't do anything at all. */
539 ex numeric::eval(int level) const
541 // Warning: if this is ever gonna do something, the ex ctors from all kinds
542 // of numbers should be checking for status_flags::evaluated.
547 /** Cast numeric into a floating-point object. For example exact numeric(1) is
548 * returned as a 1.0000000000000000000000 and so on according to how Digits is
549 * currently set. In case the object already was a floating point number the
550 * precision is trimmed to match the currently set default.
552 * @param level ignored, only needed for overriding basic::evalf.
553 * @return an ex-handle to a numeric. */
554 ex numeric::evalf(int level) const
556 // level can safely be discarded for numeric objects.
557 return numeric(cln::cl_float(1.0, cln::default_float_format) *
558 (cln::the<cln::cl_N>(value)));
563 int numeric::compare_same_type(const basic &other) const
565 GINAC_ASSERT(is_exactly_a<numeric>(other));
566 const numeric &o = static_cast<const numeric &>(other);
568 return this->compare(o);
572 bool numeric::is_equal_same_type(const basic &other) const
574 GINAC_ASSERT(is_exactly_a<numeric>(other));
575 const numeric &o = static_cast<const numeric &>(other);
577 return this->is_equal(o);
581 unsigned numeric::calchash(void) const
583 // Base computation of hashvalue on CLN's hashcode. Note: That depends
584 // only on the number's value, not its type or precision (i.e. a true
585 // equivalence relation on numbers). As a consequence, 3 and 3.0 share
586 // the same hashvalue. That shouldn't really matter, though.
587 setflag(status_flags::hash_calculated);
588 hashvalue = golden_ratio_hash(cln::equal_hashcode(cln::the<cln::cl_N>(value)));
594 // new virtual functions which can be overridden by derived classes
600 // non-virtual functions in this class
605 /** Numerical addition method. Adds argument to *this and returns result as
606 * a numeric object. */
607 const numeric numeric::add(const numeric &other) const
609 // Efficiency shortcut: trap the neutral element by pointer.
612 else if (&other==_num0_p)
615 return numeric(cln::the<cln::cl_N>(value)+cln::the<cln::cl_N>(other.value));
619 /** Numerical subtraction method. Subtracts argument from *this and returns
620 * result as a numeric object. */
621 const numeric numeric::sub(const numeric &other) const
623 return numeric(cln::the<cln::cl_N>(value)-cln::the<cln::cl_N>(other.value));
627 /** Numerical multiplication method. Multiplies *this and argument and returns
628 * result as a numeric object. */
629 const numeric numeric::mul(const numeric &other) const
631 // Efficiency shortcut: trap the neutral element by pointer.
634 else if (&other==_num1_p)
637 return numeric(cln::the<cln::cl_N>(value)*cln::the<cln::cl_N>(other.value));
641 /** Numerical division method. Divides *this by argument and returns result as
644 * @exception overflow_error (division by zero) */
645 const numeric numeric::div(const numeric &other) const
647 if (cln::zerop(cln::the<cln::cl_N>(other.value)))
648 throw std::overflow_error("numeric::div(): division by zero");
649 return numeric(cln::the<cln::cl_N>(value)/cln::the<cln::cl_N>(other.value));
653 /** Numerical exponentiation. Raises *this to the power given as argument and
654 * returns result as a numeric object. */
655 const numeric numeric::power(const numeric &other) const
657 // Efficiency shortcut: trap the neutral exponent by pointer.
661 if (cln::zerop(cln::the<cln::cl_N>(value))) {
662 if (cln::zerop(cln::the<cln::cl_N>(other.value)))
663 throw std::domain_error("numeric::eval(): pow(0,0) is undefined");
664 else if (cln::zerop(cln::realpart(cln::the<cln::cl_N>(other.value))))
665 throw std::domain_error("numeric::eval(): pow(0,I) is undefined");
666 else if (cln::minusp(cln::realpart(cln::the<cln::cl_N>(other.value))))
667 throw std::overflow_error("numeric::eval(): division by zero");
671 return numeric(cln::expt(cln::the<cln::cl_N>(value),cln::the<cln::cl_N>(other.value)));
676 /** Numerical addition method. Adds argument to *this and returns result as
677 * a numeric object on the heap. Use internally only for direct wrapping into
678 * an ex object, where the result would end up on the heap anyways. */
679 const numeric &numeric::add_dyn(const numeric &other) const
681 // Efficiency shortcut: trap the neutral element by pointer.
684 else if (&other==_num0_p)
687 return static_cast<const numeric &>((new numeric(cln::the<cln::cl_N>(value)+cln::the<cln::cl_N>(other.value)))->
688 setflag(status_flags::dynallocated));
692 /** Numerical subtraction method. Subtracts argument from *this and returns
693 * result as a numeric object on the heap. Use internally only for direct
694 * wrapping into an ex object, where the result would end up on the heap
696 const numeric &numeric::sub_dyn(const numeric &other) const
698 return static_cast<const numeric &>((new numeric(cln::the<cln::cl_N>(value)-cln::the<cln::cl_N>(other.value)))->
699 setflag(status_flags::dynallocated));
703 /** Numerical multiplication method. Multiplies *this and argument and returns
704 * result as a numeric object on the heap. Use internally only for direct
705 * wrapping into an ex object, where the result would end up on the heap
707 const numeric &numeric::mul_dyn(const numeric &other) const
709 // Efficiency shortcut: trap the neutral element by pointer.
712 else if (&other==_num1_p)
715 return static_cast<const numeric &>((new numeric(cln::the<cln::cl_N>(value)*cln::the<cln::cl_N>(other.value)))->
716 setflag(status_flags::dynallocated));
720 /** Numerical division method. Divides *this by argument and returns result as
721 * a numeric object on the heap. Use internally only for direct wrapping
722 * into an ex object, where the result would end up on the heap
725 * @exception overflow_error (division by zero) */
726 const numeric &numeric::div_dyn(const numeric &other) const
728 if (cln::zerop(cln::the<cln::cl_N>(other.value)))
729 throw std::overflow_error("division by zero");
730 return static_cast<const numeric &>((new numeric(cln::the<cln::cl_N>(value)/cln::the<cln::cl_N>(other.value)))->
731 setflag(status_flags::dynallocated));
735 /** Numerical exponentiation. Raises *this to the power given as argument and
736 * returns result as a numeric object on the heap. Use internally only for
737 * direct wrapping into an ex object, where the result would end up on the
739 const numeric &numeric::power_dyn(const numeric &other) const
741 // Efficiency shortcut: trap the neutral exponent by pointer.
745 if (cln::zerop(cln::the<cln::cl_N>(value))) {
746 if (cln::zerop(cln::the<cln::cl_N>(other.value)))
747 throw std::domain_error("numeric::eval(): pow(0,0) is undefined");
748 else if (cln::zerop(cln::realpart(cln::the<cln::cl_N>(other.value))))
749 throw std::domain_error("numeric::eval(): pow(0,I) is undefined");
750 else if (cln::minusp(cln::realpart(cln::the<cln::cl_N>(other.value))))
751 throw std::overflow_error("numeric::eval(): division by zero");
755 return static_cast<const numeric &>((new numeric(cln::expt(cln::the<cln::cl_N>(value),cln::the<cln::cl_N>(other.value))))->
756 setflag(status_flags::dynallocated));
760 const numeric &numeric::operator=(int i)
762 return operator=(numeric(i));
766 const numeric &numeric::operator=(unsigned int i)
768 return operator=(numeric(i));
772 const numeric &numeric::operator=(long i)
774 return operator=(numeric(i));
778 const numeric &numeric::operator=(unsigned long i)
780 return operator=(numeric(i));
784 const numeric &numeric::operator=(double d)
786 return operator=(numeric(d));
790 const numeric &numeric::operator=(const char * s)
792 return operator=(numeric(s));
796 /** Inverse of a number. */
797 const numeric numeric::inverse(void) const
799 if (cln::zerop(cln::the<cln::cl_N>(value)))
800 throw std::overflow_error("numeric::inverse(): division by zero");
801 return numeric(cln::recip(cln::the<cln::cl_N>(value)));
805 /** Return the complex half-plane (left or right) in which the number lies.
806 * csgn(x)==0 for x==0, csgn(x)==1 for Re(x)>0 or Re(x)=0 and Im(x)>0,
807 * csgn(x)==-1 for Re(x)<0 or Re(x)=0 and Im(x)<0.
809 * @see numeric::compare(const numeric &other) */
810 int numeric::csgn(void) const
812 if (cln::zerop(cln::the<cln::cl_N>(value)))
814 cln::cl_R r = cln::realpart(cln::the<cln::cl_N>(value));
815 if (!cln::zerop(r)) {
821 if (cln::plusp(cln::imagpart(cln::the<cln::cl_N>(value))))
829 /** This method establishes a canonical order on all numbers. For complex
830 * numbers this is not possible in a mathematically consistent way but we need
831 * to establish some order and it ought to be fast. So we simply define it
832 * to be compatible with our method csgn.
834 * @return csgn(*this-other)
835 * @see numeric::csgn(void) */
836 int numeric::compare(const numeric &other) const
838 // Comparing two real numbers?
839 if (cln::instanceof(value, cln::cl_R_ring) &&
840 cln::instanceof(other.value, cln::cl_R_ring))
841 // Yes, so just cln::compare them
842 return cln::compare(cln::the<cln::cl_R>(value), cln::the<cln::cl_R>(other.value));
844 // No, first cln::compare real parts...
845 cl_signean real_cmp = cln::compare(cln::realpart(cln::the<cln::cl_N>(value)), cln::realpart(cln::the<cln::cl_N>(other.value)));
848 // ...and then the imaginary parts.
849 return cln::compare(cln::imagpart(cln::the<cln::cl_N>(value)), cln::imagpart(cln::the<cln::cl_N>(other.value)));
854 bool numeric::is_equal(const numeric &other) const
856 return cln::equal(cln::the<cln::cl_N>(value),cln::the<cln::cl_N>(other.value));
860 /** True if object is zero. */
861 bool numeric::is_zero(void) const
863 return cln::zerop(cln::the<cln::cl_N>(value));
867 /** True if object is not complex and greater than zero. */
868 bool numeric::is_positive(void) const
871 return cln::plusp(cln::the<cln::cl_R>(value));
876 /** True if object is not complex and less than zero. */
877 bool numeric::is_negative(void) const
880 return cln::minusp(cln::the<cln::cl_R>(value));
885 /** True if object is a non-complex integer. */
886 bool numeric::is_integer(void) const
888 return cln::instanceof(value, cln::cl_I_ring);
892 /** True if object is an exact integer greater than zero. */
893 bool numeric::is_pos_integer(void) const
895 return (this->is_integer() && cln::plusp(cln::the<cln::cl_I>(value)));
899 /** True if object is an exact integer greater or equal zero. */
900 bool numeric::is_nonneg_integer(void) const
902 return (this->is_integer() && !cln::minusp(cln::the<cln::cl_I>(value)));
906 /** True if object is an exact even integer. */
907 bool numeric::is_even(void) const
909 return (this->is_integer() && cln::evenp(cln::the<cln::cl_I>(value)));
913 /** True if object is an exact odd integer. */
914 bool numeric::is_odd(void) const
916 return (this->is_integer() && cln::oddp(cln::the<cln::cl_I>(value)));
920 /** Probabilistic primality test.
922 * @return true if object is exact integer and prime. */
923 bool numeric::is_prime(void) const
925 return (this->is_integer() && cln::isprobprime(cln::the<cln::cl_I>(value)));
929 /** True if object is an exact rational number, may even be complex
930 * (denominator may be unity). */
931 bool numeric::is_rational(void) const
933 return cln::instanceof(value, cln::cl_RA_ring);
937 /** True if object is a real integer, rational or float (but not complex). */
938 bool numeric::is_real(void) const
940 return cln::instanceof(value, cln::cl_R_ring);
944 bool numeric::operator==(const numeric &other) const
946 return cln::equal(cln::the<cln::cl_N>(value), cln::the<cln::cl_N>(other.value));
950 bool numeric::operator!=(const numeric &other) const
952 return !cln::equal(cln::the<cln::cl_N>(value), cln::the<cln::cl_N>(other.value));
956 /** True if object is element of the domain of integers extended by I, i.e. is
957 * of the form a+b*I, where a and b are integers. */
958 bool numeric::is_cinteger(void) const
960 if (cln::instanceof(value, cln::cl_I_ring))
962 else if (!this->is_real()) { // complex case, handle n+m*I
963 if (cln::instanceof(cln::realpart(cln::the<cln::cl_N>(value)), cln::cl_I_ring) &&
964 cln::instanceof(cln::imagpart(cln::the<cln::cl_N>(value)), cln::cl_I_ring))
971 /** True if object is an exact rational number, may even be complex
972 * (denominator may be unity). */
973 bool numeric::is_crational(void) const
975 if (cln::instanceof(value, cln::cl_RA_ring))
977 else if (!this->is_real()) { // complex case, handle Q(i):
978 if (cln::instanceof(cln::realpart(cln::the<cln::cl_N>(value)), cln::cl_RA_ring) &&
979 cln::instanceof(cln::imagpart(cln::the<cln::cl_N>(value)), cln::cl_RA_ring))
986 /** Numerical comparison: less.
988 * @exception invalid_argument (complex inequality) */
989 bool numeric::operator<(const numeric &other) const
991 if (this->is_real() && other.is_real())
992 return (cln::the<cln::cl_R>(value) < cln::the<cln::cl_R>(other.value));
993 throw std::invalid_argument("numeric::operator<(): complex inequality");
997 /** Numerical comparison: less or equal.
999 * @exception invalid_argument (complex inequality) */
1000 bool numeric::operator<=(const numeric &other) const
1002 if (this->is_real() && other.is_real())
1003 return (cln::the<cln::cl_R>(value) <= cln::the<cln::cl_R>(other.value));
1004 throw std::invalid_argument("numeric::operator<=(): complex inequality");
1008 /** Numerical comparison: greater.
1010 * @exception invalid_argument (complex inequality) */
1011 bool numeric::operator>(const numeric &other) const
1013 if (this->is_real() && other.is_real())
1014 return (cln::the<cln::cl_R>(value) > cln::the<cln::cl_R>(other.value));
1015 throw std::invalid_argument("numeric::operator>(): complex inequality");
1019 /** Numerical comparison: greater or equal.
1021 * @exception invalid_argument (complex inequality) */
1022 bool numeric::operator>=(const numeric &other) const
1024 if (this->is_real() && other.is_real())
1025 return (cln::the<cln::cl_R>(value) >= cln::the<cln::cl_R>(other.value));
1026 throw std::invalid_argument("numeric::operator>=(): complex inequality");
1030 /** Converts numeric types to machine's int. You should check with
1031 * is_integer() if the number is really an integer before calling this method.
1032 * You may also consider checking the range first. */
1033 int numeric::to_int(void) const
1035 GINAC_ASSERT(this->is_integer());
1036 return cln::cl_I_to_int(cln::the<cln::cl_I>(value));
1040 /** Converts numeric types to machine's long. You should check with
1041 * is_integer() if the number is really an integer before calling this method.
1042 * You may also consider checking the range first. */
1043 long numeric::to_long(void) const
1045 GINAC_ASSERT(this->is_integer());
1046 return cln::cl_I_to_long(cln::the<cln::cl_I>(value));
1050 /** Converts numeric types to machine's double. You should check with is_real()
1051 * if the number is really not complex before calling this method. */
1052 double numeric::to_double(void) const
1054 GINAC_ASSERT(this->is_real());
1055 return cln::double_approx(cln::realpart(cln::the<cln::cl_N>(value)));
1059 /** Returns a new CLN object of type cl_N, representing the value of *this.
1060 * This method may be used when mixing GiNaC and CLN in one project.
1062 cln::cl_N numeric::to_cl_N(void) const
1064 return cln::cl_N(cln::the<cln::cl_N>(value));
1068 /** Real part of a number. */
1069 const numeric numeric::real(void) const
1071 return numeric(cln::realpart(cln::the<cln::cl_N>(value)));
1075 /** Imaginary part of a number. */
1076 const numeric numeric::imag(void) const
1078 return numeric(cln::imagpart(cln::the<cln::cl_N>(value)));
1082 /** Numerator. Computes the numerator of rational numbers, rationalized
1083 * numerator of complex if real and imaginary part are both rational numbers
1084 * (i.e numer(4/3+5/6*I) == 8+5*I), the number carrying the sign in all other
1086 const numeric numeric::numer(void) const
1088 if (this->is_integer())
1089 return numeric(*this);
1091 else if (cln::instanceof(value, cln::cl_RA_ring))
1092 return numeric(cln::numerator(cln::the<cln::cl_RA>(value)));
1094 else if (!this->is_real()) { // complex case, handle Q(i):
1095 const cln::cl_RA r = cln::the<cln::cl_RA>(cln::realpart(cln::the<cln::cl_N>(value)));
1096 const cln::cl_RA i = cln::the<cln::cl_RA>(cln::imagpart(cln::the<cln::cl_N>(value)));
1097 if (cln::instanceof(r, cln::cl_I_ring) && cln::instanceof(i, cln::cl_I_ring))
1098 return numeric(*this);
1099 if (cln::instanceof(r, cln::cl_I_ring) && cln::instanceof(i, cln::cl_RA_ring))
1100 return numeric(cln::complex(r*cln::denominator(i), cln::numerator(i)));
1101 if (cln::instanceof(r, cln::cl_RA_ring) && cln::instanceof(i, cln::cl_I_ring))
1102 return numeric(cln::complex(cln::numerator(r), i*cln::denominator(r)));
1103 if (cln::instanceof(r, cln::cl_RA_ring) && cln::instanceof(i, cln::cl_RA_ring)) {
1104 const cln::cl_I s = cln::lcm(cln::denominator(r), cln::denominator(i));
1105 return numeric(cln::complex(cln::numerator(r)*(cln::exquo(s,cln::denominator(r))),
1106 cln::numerator(i)*(cln::exquo(s,cln::denominator(i)))));
1109 // at least one float encountered
1110 return numeric(*this);
1114 /** Denominator. Computes the denominator of rational numbers, common integer
1115 * denominator of complex if real and imaginary part are both rational numbers
1116 * (i.e denom(4/3+5/6*I) == 6), one in all other cases. */
1117 const numeric numeric::denom(void) const
1119 if (this->is_integer())
1122 if (cln::instanceof(value, cln::cl_RA_ring))
1123 return numeric(cln::denominator(cln::the<cln::cl_RA>(value)));
1125 if (!this->is_real()) { // complex case, handle Q(i):
1126 const cln::cl_RA r = cln::the<cln::cl_RA>(cln::realpart(cln::the<cln::cl_N>(value)));
1127 const cln::cl_RA i = cln::the<cln::cl_RA>(cln::imagpart(cln::the<cln::cl_N>(value)));
1128 if (cln::instanceof(r, cln::cl_I_ring) && cln::instanceof(i, cln::cl_I_ring))
1130 if (cln::instanceof(r, cln::cl_I_ring) && cln::instanceof(i, cln::cl_RA_ring))
1131 return numeric(cln::denominator(i));
1132 if (cln::instanceof(r, cln::cl_RA_ring) && cln::instanceof(i, cln::cl_I_ring))
1133 return numeric(cln::denominator(r));
1134 if (cln::instanceof(r, cln::cl_RA_ring) && cln::instanceof(i, cln::cl_RA_ring))
1135 return numeric(cln::lcm(cln::denominator(r), cln::denominator(i)));
1137 // at least one float encountered
1142 /** Size in binary notation. For integers, this is the smallest n >= 0 such
1143 * that -2^n <= x < 2^n. If x > 0, this is the unique n > 0 such that
1144 * 2^(n-1) <= x < 2^n.
1146 * @return number of bits (excluding sign) needed to represent that number
1147 * in two's complement if it is an integer, 0 otherwise. */
1148 int numeric::int_length(void) const
1150 if (this->is_integer())
1151 return cln::integer_length(cln::the<cln::cl_I>(value));
1160 /** Imaginary unit. This is not a constant but a numeric since we are
1161 * natively handing complex numbers anyways, so in each expression containing
1162 * an I it is automatically eval'ed away anyhow. */
1163 const numeric I = numeric(cln::complex(cln::cl_I(0),cln::cl_I(1)));
1166 /** Exponential function.
1168 * @return arbitrary precision numerical exp(x). */
1169 const numeric exp(const numeric &x)
1171 return cln::exp(x.to_cl_N());
1175 /** Natural logarithm.
1177 * @param z complex number
1178 * @return arbitrary precision numerical log(x).
1179 * @exception pole_error("log(): logarithmic pole",0) */
1180 const numeric log(const numeric &z)
1183 throw pole_error("log(): logarithmic pole",0);
1184 return cln::log(z.to_cl_N());
1188 /** Numeric sine (trigonometric function).
1190 * @return arbitrary precision numerical sin(x). */
1191 const numeric sin(const numeric &x)
1193 return cln::sin(x.to_cl_N());
1197 /** Numeric cosine (trigonometric function).
1199 * @return arbitrary precision numerical cos(x). */
1200 const numeric cos(const numeric &x)
1202 return cln::cos(x.to_cl_N());
1206 /** Numeric tangent (trigonometric function).
1208 * @return arbitrary precision numerical tan(x). */
1209 const numeric tan(const numeric &x)
1211 return cln::tan(x.to_cl_N());
1215 /** Numeric inverse sine (trigonometric function).
1217 * @return arbitrary precision numerical asin(x). */
1218 const numeric asin(const numeric &x)
1220 return cln::asin(x.to_cl_N());
1224 /** Numeric inverse cosine (trigonometric function).
1226 * @return arbitrary precision numerical acos(x). */
1227 const numeric acos(const numeric &x)
1229 return cln::acos(x.to_cl_N());
1235 * @param z complex number
1237 * @exception pole_error("atan(): logarithmic pole",0) */
1238 const numeric atan(const numeric &x)
1241 x.real().is_zero() &&
1242 abs(x.imag()).is_equal(_num1))
1243 throw pole_error("atan(): logarithmic pole",0);
1244 return cln::atan(x.to_cl_N());
1250 * @param x real number
1251 * @param y real number
1252 * @return atan(y/x) */
1253 const numeric atan(const numeric &y, const numeric &x)
1255 if (x.is_real() && y.is_real())
1256 return cln::atan(cln::the<cln::cl_R>(x.to_cl_N()),
1257 cln::the<cln::cl_R>(y.to_cl_N()));
1259 throw std::invalid_argument("atan(): complex argument");
1263 /** Numeric hyperbolic sine (trigonometric function).
1265 * @return arbitrary precision numerical sinh(x). */
1266 const numeric sinh(const numeric &x)
1268 return cln::sinh(x.to_cl_N());
1272 /** Numeric hyperbolic cosine (trigonometric function).
1274 * @return arbitrary precision numerical cosh(x). */
1275 const numeric cosh(const numeric &x)
1277 return cln::cosh(x.to_cl_N());
1281 /** Numeric hyperbolic tangent (trigonometric function).
1283 * @return arbitrary precision numerical tanh(x). */
1284 const numeric tanh(const numeric &x)
1286 return cln::tanh(x.to_cl_N());
1290 /** Numeric inverse hyperbolic sine (trigonometric function).
1292 * @return arbitrary precision numerical asinh(x). */
1293 const numeric asinh(const numeric &x)
1295 return cln::asinh(x.to_cl_N());
1299 /** Numeric inverse hyperbolic cosine (trigonometric function).
1301 * @return arbitrary precision numerical acosh(x). */
1302 const numeric acosh(const numeric &x)
1304 return cln::acosh(x.to_cl_N());
1308 /** Numeric inverse hyperbolic tangent (trigonometric function).
1310 * @return arbitrary precision numerical atanh(x). */
1311 const numeric atanh(const numeric &x)
1313 return cln::atanh(x.to_cl_N());
1317 /*static cln::cl_N Li2_series(const ::cl_N &x,
1318 const ::float_format_t &prec)
1320 // Note: argument must be in the unit circle
1321 // This is very inefficient unless we have fast floating point Bernoulli
1322 // numbers implemented!
1323 cln::cl_N c1 = -cln::log(1-x);
1325 // hard-wire the first two Bernoulli numbers
1326 cln::cl_N acc = c1 - cln::square(c1)/4;
1328 cln::cl_F pisq = cln::square(cln::cl_pi(prec)); // pi^2
1329 cln::cl_F piac = cln::cl_float(1, prec); // accumulator: pi^(2*i)
1331 c1 = cln::square(c1);
1335 aug = c2 * (*(bernoulli(numeric(2*i)).clnptr())) / cln::factorial(2*i+1);
1336 // aug = c2 * cln::cl_I(i%2 ? 1 : -1) / cln::cl_I(2*i+1) * cln::cl_zeta(2*i, prec) / piac / (cln::cl_I(1)<<(2*i-1));
1339 } while (acc != acc+aug);
1343 /** Numeric evaluation of Dilogarithm within circle of convergence (unit
1344 * circle) using a power series. */
1345 static cln::cl_N Li2_series(const cln::cl_N &x,
1346 const cln::float_format_t &prec)
1348 // Note: argument must be in the unit circle
1350 cln::cl_N num = cln::complex(cln::cl_float(1, prec), 0);
1355 den = den + i; // 1, 4, 9, 16, ...
1359 } while (acc != acc+aug);
1363 /** Folds Li2's argument inside a small rectangle to enhance convergence. */
1364 static cln::cl_N Li2_projection(const cln::cl_N &x,
1365 const cln::float_format_t &prec)
1367 const cln::cl_R re = cln::realpart(x);
1368 const cln::cl_R im = cln::imagpart(x);
1369 if (re > cln::cl_F(".5"))
1370 // zeta(2) - Li2(1-x) - log(x)*log(1-x)
1372 - Li2_series(1-x, prec)
1373 - cln::log(x)*cln::log(1-x));
1374 if ((re <= 0 && cln::abs(im) > cln::cl_F(".75")) || (re < cln::cl_F("-.5")))
1375 // -log(1-x)^2 / 2 - Li2(x/(x-1))
1376 return(- cln::square(cln::log(1-x))/2
1377 - Li2_series(x/(x-1), prec));
1378 if (re > 0 && cln::abs(im) > cln::cl_LF(".75"))
1379 // Li2(x^2)/2 - Li2(-x)
1380 return(Li2_projection(cln::square(x), prec)/2
1381 - Li2_projection(-x, prec));
1382 return Li2_series(x, prec);
1385 /** Numeric evaluation of Dilogarithm. The domain is the entire complex plane,
1386 * the branch cut lies along the positive real axis, starting at 1 and
1387 * continuous with quadrant IV.
1389 * @return arbitrary precision numerical Li2(x). */
1390 const numeric Li2(const numeric &x)
1395 // what is the desired float format?
1396 // first guess: default format
1397 cln::float_format_t prec = cln::default_float_format;
1398 const cln::cl_N value = x.to_cl_N();
1399 // second guess: the argument's format
1400 if (!x.real().is_rational())
1401 prec = cln::float_format(cln::the<cln::cl_F>(cln::realpart(value)));
1402 else if (!x.imag().is_rational())
1403 prec = cln::float_format(cln::the<cln::cl_F>(cln::imagpart(value)));
1405 if (cln::the<cln::cl_N>(value)==1) // may cause trouble with log(1-x)
1406 return cln::zeta(2, prec);
1408 if (cln::abs(value) > 1)
1409 // -log(-x)^2 / 2 - zeta(2) - Li2(1/x)
1410 return(- cln::square(cln::log(-value))/2
1411 - cln::zeta(2, prec)
1412 - Li2_projection(cln::recip(value), prec));
1414 return Li2_projection(x.to_cl_N(), prec);
1418 /** Numeric evaluation of Riemann's Zeta function. Currently works only for
1419 * integer arguments. */
1420 const numeric zeta(const numeric &x)
1422 // A dirty hack to allow for things like zeta(3.0), since CLN currently
1423 // only knows about integer arguments and zeta(3).evalf() automatically
1424 // cascades down to zeta(3.0).evalf(). The trick is to rely on 3.0-3
1425 // being an exact zero for CLN, which can be tested and then we can just
1426 // pass the number casted to an int:
1428 const int aux = (int)(cln::double_approx(cln::the<cln::cl_R>(x.to_cl_N())));
1429 if (cln::zerop(x.to_cl_N()-aux))
1430 return cln::zeta(aux);
1436 /** The Gamma function.
1437 * This is only a stub! */
1438 const numeric lgamma(const numeric &x)
1442 const numeric tgamma(const numeric &x)
1448 /** The psi function (aka polygamma function).
1449 * This is only a stub! */
1450 const numeric psi(const numeric &x)
1456 /** The psi functions (aka polygamma functions).
1457 * This is only a stub! */
1458 const numeric psi(const numeric &n, const numeric &x)
1464 /** Factorial combinatorial function.
1466 * @param n integer argument >= 0
1467 * @exception range_error (argument must be integer >= 0) */
1468 const numeric factorial(const numeric &n)
1470 if (!n.is_nonneg_integer())
1471 throw std::range_error("numeric::factorial(): argument must be integer >= 0");
1472 return numeric(cln::factorial(n.to_int()));
1476 /** The double factorial combinatorial function. (Scarcely used, but still
1477 * useful in cases, like for exact results of tgamma(n+1/2) for instance.)
1479 * @param n integer argument >= -1
1480 * @return n!! == n * (n-2) * (n-4) * ... * ({1|2}) with 0!! == (-1)!! == 1
1481 * @exception range_error (argument must be integer >= -1) */
1482 const numeric doublefactorial(const numeric &n)
1484 if (n.is_equal(_num_1))
1487 if (!n.is_nonneg_integer())
1488 throw std::range_error("numeric::doublefactorial(): argument must be integer >= -1");
1490 return numeric(cln::doublefactorial(n.to_int()));
1494 /** The Binomial coefficients. It computes the binomial coefficients. For
1495 * integer n and k and positive n this is the number of ways of choosing k
1496 * objects from n distinct objects. If n is negative, the formula
1497 * binomial(n,k) == (-1)^k*binomial(k-n-1,k) is used to compute the result. */
1498 const numeric binomial(const numeric &n, const numeric &k)
1500 if (n.is_integer() && k.is_integer()) {
1501 if (n.is_nonneg_integer()) {
1502 if (k.compare(n)!=1 && k.compare(_num0)!=-1)
1503 return numeric(cln::binomial(n.to_int(),k.to_int()));
1507 return _num_1.power(k)*binomial(k-n-_num1,k);
1511 // should really be gamma(n+1)/gamma(r+1)/gamma(n-r+1) or a suitable limit
1512 throw std::range_error("numeric::binomial(): don´t know how to evaluate that.");
1516 /** Bernoulli number. The nth Bernoulli number is the coefficient of x^n/n!
1517 * in the expansion of the function x/(e^x-1).
1519 * @return the nth Bernoulli number (a rational number).
1520 * @exception range_error (argument must be integer >= 0) */
1521 const numeric bernoulli(const numeric &nn)
1523 if (!nn.is_integer() || nn.is_negative())
1524 throw std::range_error("numeric::bernoulli(): argument must be integer >= 0");
1528 // The Bernoulli numbers are rational numbers that may be computed using
1531 // B_n = - 1/(n+1) * sum_{k=0}^{n-1}(binomial(n+1,k)*B_k)
1533 // with B(0) = 1. Since the n'th Bernoulli number depends on all the
1534 // previous ones, the computation is necessarily very expensive. There are
1535 // several other ways of computing them, a particularly good one being
1539 // for (unsigned i=0; i<n; i++) {
1540 // c = exquo(c*(i-n),(i+2));
1541 // Bern = Bern + c*s/(i+2);
1542 // s = s + expt_pos(cl_I(i+2),n);
1546 // But if somebody works with the n'th Bernoulli number she is likely to
1547 // also need all previous Bernoulli numbers. So we need a complete remember
1548 // table and above divide and conquer algorithm is not suited to build one
1549 // up. The formula below accomplishes this. It is a modification of the
1550 // defining formula above but the computation of the binomial coefficients
1551 // is carried along in an inline fashion. It also honors the fact that
1552 // B_n is zero when n is odd and greater than 1.
1554 // (There is an interesting relation with the tangent polynomials described
1555 // in `Concrete Mathematics', which leads to a program a little faster as
1556 // our implementation below, but it requires storing one such polynomial in
1557 // addition to the remember table. This doubles the memory footprint so
1558 // we don't use it.)
1560 const unsigned n = nn.to_int();
1562 // the special cases not covered by the algorithm below
1564 return (n==1) ? _num_1_2 : _num0;
1568 // store nonvanishing Bernoulli numbers here
1569 static std::vector< cln::cl_RA > results;
1570 static unsigned next_r = 0;
1572 // algorithm not applicable to B(2), so just store it
1574 results.push_back(cln::recip(cln::cl_RA(6)));
1578 return results[n/2-1];
1580 results.reserve(n/2);
1581 for (unsigned p=next_r; p<=n; p+=2) {
1582 cln::cl_I c = 1; // seed for binonmial coefficients
1583 cln::cl_RA b = cln::cl_RA(1-p)/2;
1584 const unsigned p3 = p+3;
1585 const unsigned pm = p-2;
1587 // test if intermediate unsigned int can be represented by immediate
1588 // objects by CLN (i.e. < 2^29 for 32 Bit machines, see <cln/object.h>)
1589 if (p < (1UL<<cl_value_len/2)) {
1590 for (i=2, k=1, p_2=p/2; i<=pm; i+=2, ++k, --p_2) {
1591 c = cln::exquo(c * ((p3-i) * p_2), (i-1)*k);
1592 b = b + c*results[k-1];
1595 for (i=2, k=1, p_2=p/2; i<=pm; i+=2, ++k, --p_2) {
1596 c = cln::exquo((c * (p3-i)) * p_2, cln::cl_I(i-1)*k);
1597 b = b + c*results[k-1];
1600 results.push_back(-b/(p+1));
1603 return results[n/2-1];
1607 /** Fibonacci number. The nth Fibonacci number F(n) is defined by the
1608 * recurrence formula F(n)==F(n-1)+F(n-2) with F(0)==0 and F(1)==1.
1610 * @param n an integer
1611 * @return the nth Fibonacci number F(n) (an integer number)
1612 * @exception range_error (argument must be an integer) */
1613 const numeric fibonacci(const numeric &n)
1615 if (!n.is_integer())
1616 throw std::range_error("numeric::fibonacci(): argument must be integer");
1619 // The following addition formula holds:
1621 // F(n+m) = F(m-1)*F(n) + F(m)*F(n+1) for m >= 1, n >= 0.
1623 // (Proof: For fixed m, the LHS and the RHS satisfy the same recurrence
1624 // w.r.t. n, and the initial values (n=0, n=1) agree. Hence all values
1626 // Replace m by m+1:
1627 // F(n+m+1) = F(m)*F(n) + F(m+1)*F(n+1) for m >= 0, n >= 0
1628 // Now put in m = n, to get
1629 // F(2n) = (F(n+1)-F(n))*F(n) + F(n)*F(n+1) = F(n)*(2*F(n+1) - F(n))
1630 // F(2n+1) = F(n)^2 + F(n+1)^2
1632 // F(2n+2) = F(n+1)*(2*F(n) + F(n+1))
1635 if (n.is_negative())
1637 return -fibonacci(-n);
1639 return fibonacci(-n);
1643 cln::cl_I m = cln::the<cln::cl_I>(n.to_cl_N()) >> 1L; // floor(n/2);
1644 for (uintL bit=cln::integer_length(m); bit>0; --bit) {
1645 // Since a squaring is cheaper than a multiplication, better use
1646 // three squarings instead of one multiplication and two squarings.
1647 cln::cl_I u2 = cln::square(u);
1648 cln::cl_I v2 = cln::square(v);
1649 if (cln::logbitp(bit-1, m)) {
1650 v = cln::square(u + v) - u2;
1653 u = v2 - cln::square(v - u);
1658 // Here we don't use the squaring formula because one multiplication
1659 // is cheaper than two squarings.
1660 return u * ((v << 1) - u);
1662 return cln::square(u) + cln::square(v);
1666 /** Absolute value. */
1667 const numeric abs(const numeric& x)
1669 return cln::abs(x.to_cl_N());
1673 /** Modulus (in positive representation).
1674 * In general, mod(a,b) has the sign of b or is zero, and rem(a,b) has the
1675 * sign of a or is zero. This is different from Maple's modp, where the sign
1676 * of b is ignored. It is in agreement with Mathematica's Mod.
1678 * @return a mod b in the range [0,abs(b)-1] with sign of b if both are
1679 * integer, 0 otherwise. */
1680 const numeric mod(const numeric &a, const numeric &b)
1682 if (a.is_integer() && b.is_integer())
1683 return cln::mod(cln::the<cln::cl_I>(a.to_cl_N()),
1684 cln::the<cln::cl_I>(b.to_cl_N()));
1690 /** Modulus (in symmetric representation).
1691 * Equivalent to Maple's mods.
1693 * @return a mod b in the range [-iquo(abs(m)-1,2), iquo(abs(m),2)]. */
1694 const numeric smod(const numeric &a, const numeric &b)
1696 if (a.is_integer() && b.is_integer()) {
1697 const cln::cl_I b2 = cln::ceiling1(cln::the<cln::cl_I>(b.to_cl_N()) >> 1) - 1;
1698 return cln::mod(cln::the<cln::cl_I>(a.to_cl_N()) + b2,
1699 cln::the<cln::cl_I>(b.to_cl_N())) - b2;
1705 /** Numeric integer remainder.
1706 * Equivalent to Maple's irem(a,b) as far as sign conventions are concerned.
1707 * In general, mod(a,b) has the sign of b or is zero, and irem(a,b) has the
1708 * sign of a or is zero.
1710 * @return remainder of a/b if both are integer, 0 otherwise. */
1711 const numeric irem(const numeric &a, const numeric &b)
1713 if (a.is_integer() && b.is_integer())
1714 return cln::rem(cln::the<cln::cl_I>(a.to_cl_N()),
1715 cln::the<cln::cl_I>(b.to_cl_N()));
1721 /** Numeric integer remainder.
1722 * Equivalent to Maple's irem(a,b,'q') it obeyes the relation
1723 * irem(a,b,q) == a - q*b. In general, mod(a,b) has the sign of b or is zero,
1724 * and irem(a,b) has the sign of a or is zero.
1726 * @return remainder of a/b and quotient stored in q if both are integer,
1728 const numeric irem(const numeric &a, const numeric &b, numeric &q)
1730 if (a.is_integer() && b.is_integer()) {
1731 const cln::cl_I_div_t rem_quo = cln::truncate2(cln::the<cln::cl_I>(a.to_cl_N()),
1732 cln::the<cln::cl_I>(b.to_cl_N()));
1733 q = rem_quo.quotient;
1734 return rem_quo.remainder;
1742 /** Numeric integer quotient.
1743 * Equivalent to Maple's iquo as far as sign conventions are concerned.
1745 * @return truncated quotient of a/b if both are integer, 0 otherwise. */
1746 const numeric iquo(const numeric &a, const numeric &b)
1748 if (a.is_integer() && b.is_integer())
1749 return cln::truncate1(cln::the<cln::cl_I>(a.to_cl_N()),
1750 cln::the<cln::cl_I>(b.to_cl_N()));
1756 /** Numeric integer quotient.
1757 * Equivalent to Maple's iquo(a,b,'r') it obeyes the relation
1758 * r == a - iquo(a,b,r)*b.
1760 * @return truncated quotient of a/b and remainder stored in r if both are
1761 * integer, 0 otherwise. */
1762 const numeric iquo(const numeric &a, const numeric &b, numeric &r)
1764 if (a.is_integer() && b.is_integer()) {
1765 const cln::cl_I_div_t rem_quo = cln::truncate2(cln::the<cln::cl_I>(a.to_cl_N()),
1766 cln::the<cln::cl_I>(b.to_cl_N()));
1767 r = rem_quo.remainder;
1768 return rem_quo.quotient;
1776 /** Greatest Common Divisor.
1778 * @return The GCD of two numbers if both are integer, a numerical 1
1779 * if they are not. */
1780 const numeric gcd(const numeric &a, const numeric &b)
1782 if (a.is_integer() && b.is_integer())
1783 return cln::gcd(cln::the<cln::cl_I>(a.to_cl_N()),
1784 cln::the<cln::cl_I>(b.to_cl_N()));
1790 /** Least Common Multiple.
1792 * @return The LCM of two numbers if both are integer, the product of those
1793 * two numbers if they are not. */
1794 const numeric lcm(const numeric &a, const numeric &b)
1796 if (a.is_integer() && b.is_integer())
1797 return cln::lcm(cln::the<cln::cl_I>(a.to_cl_N()),
1798 cln::the<cln::cl_I>(b.to_cl_N()));
1804 /** Numeric square root.
1805 * If possible, sqrt(z) should respect squares of exact numbers, i.e. sqrt(4)
1806 * should return integer 2.
1808 * @param z numeric argument
1809 * @return square root of z. Branch cut along negative real axis, the negative
1810 * real axis itself where imag(z)==0 and real(z)<0 belongs to the upper part
1811 * where imag(z)>0. */
1812 const numeric sqrt(const numeric &z)
1814 return cln::sqrt(z.to_cl_N());
1818 /** Integer numeric square root. */
1819 const numeric isqrt(const numeric &x)
1821 if (x.is_integer()) {
1823 cln::isqrt(cln::the<cln::cl_I>(x.to_cl_N()), &root);
1830 /** Floating point evaluation of Archimedes' constant Pi. */
1833 return numeric(cln::pi(cln::default_float_format));
1837 /** Floating point evaluation of Euler's constant gamma. */
1840 return numeric(cln::eulerconst(cln::default_float_format));
1844 /** Floating point evaluation of Catalan's constant. */
1845 ex CatalanEvalf(void)
1847 return numeric(cln::catalanconst(cln::default_float_format));
1851 /** _numeric_digits default ctor, checking for singleton invariance. */
1852 _numeric_digits::_numeric_digits()
1855 // It initializes to 17 digits, because in CLN float_format(17) turns out
1856 // to be 61 (<64) while float_format(18)=65. The reason is we want to
1857 // have a cl_LF instead of cl_SF, cl_FF or cl_DF.
1859 throw(std::runtime_error("I told you not to do instantiate me!"));
1861 cln::default_float_format = cln::float_format(17);
1865 /** Assign a native long to global Digits object. */
1866 _numeric_digits& _numeric_digits::operator=(long prec)
1869 cln::default_float_format = cln::float_format(prec);
1874 /** Convert global Digits object to native type long. */
1875 _numeric_digits::operator long()
1877 // BTW, this is approx. unsigned(cln::default_float_format*0.301)-1
1878 return (long)digits;
1882 /** Append global Digits object to ostream. */
1883 void _numeric_digits::print(std::ostream &os) const
1889 std::ostream& operator<<(std::ostream &os, const _numeric_digits &e)
1896 // static member variables
1901 bool _numeric_digits::too_late = false;
1904 /** Accuracy in decimal digits. Only object of this type! Can be set using
1905 * assignment from C++ unsigned ints and evaluated like any built-in type. */
1906 _numeric_digits Digits;
1908 } // namespace GiNaC