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) 1999-2001 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
33 #if defined(HAVE_SSTREAM)
35 #elif defined(HAVE_STRSTREAM)
38 #error Need either sstream or strstream
48 // CLN should pollute the global namespace as little as possible. Hence, we
49 // include most of it here and include only the part needed for properly
50 // declaring cln::cl_number in numeric.h. This can only be safely done in
51 // namespaced versions of CLN, i.e. version > 1.1.0. Also, we only need a
52 // subset of CLN, so we don't include the complete <cln/cln.h> but only the
54 #include <cln/output.h>
55 #include <cln/integer_io.h>
56 #include <cln/integer_ring.h>
57 #include <cln/rational_io.h>
58 #include <cln/rational_ring.h>
59 #include <cln/lfloat_class.h>
60 #include <cln/lfloat_io.h>
61 #include <cln/real_io.h>
62 #include <cln/real_ring.h>
63 #include <cln/complex_io.h>
64 #include <cln/complex_ring.h>
65 #include <cln/numtheory.h>
69 GINAC_IMPLEMENT_REGISTERED_CLASS(numeric, basic)
72 // default ctor, dtor, copy ctor assignment
73 // operator and helpers
76 /** default ctor. Numerically it initializes to an integer zero. */
77 numeric::numeric() : basic(TINFO_numeric)
79 debugmsg("numeric default ctor", LOGLEVEL_CONSTRUCT);
81 setflag(status_flags::evaluated | status_flags::expanded);
84 void numeric::copy(const numeric &other)
86 inherited::copy(other);
90 DEFAULT_DESTROY(numeric)
98 numeric::numeric(int i) : basic(TINFO_numeric)
100 debugmsg("numeric ctor from int",LOGLEVEL_CONSTRUCT);
101 // Not the whole int-range is available if we don't cast to long
102 // first. This is due to the behaviour of the cl_I-ctor, which
103 // emphasizes efficiency. However, if the integer is small enough,
104 // i.e. satisfies cl_immediate_p(), we save space and dereferences by
105 // using an immediate type:
106 if (cln::cl_immediate_p(i))
107 value = cln::cl_I(i);
109 value = cln::cl_I((long) i);
110 setflag(status_flags::evaluated | status_flags::expanded);
114 numeric::numeric(unsigned int i) : basic(TINFO_numeric)
116 debugmsg("numeric ctor from uint",LOGLEVEL_CONSTRUCT);
117 // Not the whole uint-range is available if we don't cast to ulong
118 // first. This is due to the behaviour of the cl_I-ctor, which
119 // emphasizes efficiency. However, if the integer is small enough,
120 // i.e. satisfies cl_immediate_p(), we save space and dereferences by
121 // using an immediate type:
122 if (cln::cl_immediate_p(i))
123 value = cln::cl_I(i);
125 value = cln::cl_I((unsigned long) i);
126 setflag(status_flags::evaluated | status_flags::expanded);
130 numeric::numeric(long i) : basic(TINFO_numeric)
132 debugmsg("numeric ctor from long",LOGLEVEL_CONSTRUCT);
133 value = cln::cl_I(i);
134 setflag(status_flags::evaluated | status_flags::expanded);
138 numeric::numeric(unsigned long i) : basic(TINFO_numeric)
140 debugmsg("numeric ctor from ulong",LOGLEVEL_CONSTRUCT);
141 value = cln::cl_I(i);
142 setflag(status_flags::evaluated | status_flags::expanded);
145 /** Ctor for rational numerics a/b.
147 * @exception overflow_error (division by zero) */
148 numeric::numeric(long numer, long denom) : basic(TINFO_numeric)
150 debugmsg("numeric ctor from long/long",LOGLEVEL_CONSTRUCT);
152 throw std::overflow_error("division by zero");
153 value = cln::cl_I(numer) / cln::cl_I(denom);
154 setflag(status_flags::evaluated | status_flags::expanded);
158 numeric::numeric(double d) : basic(TINFO_numeric)
160 debugmsg("numeric ctor from double",LOGLEVEL_CONSTRUCT);
161 // We really want to explicitly use the type cl_LF instead of the
162 // more general cl_F, since that would give us a cl_DF only which
163 // will not be promoted to cl_LF if overflow occurs:
164 value = cln::cl_float(d, cln::default_float_format);
165 setflag(status_flags::evaluated | status_flags::expanded);
169 /** ctor from C-style string. It also accepts complex numbers in GiNaC
170 * notation like "2+5*I". */
171 numeric::numeric(const char *s) : basic(TINFO_numeric)
173 debugmsg("numeric ctor from string",LOGLEVEL_CONSTRUCT);
174 cln::cl_N ctorval = 0;
175 // parse complex numbers (functional but not completely safe, unfortunately
176 // std::string does not understand regexpese):
177 // ss should represent a simple sum like 2+5*I
179 // make it safe by adding explicit sign
180 if (ss.at(0) != '+' && ss.at(0) != '-' && ss.at(0) != '#')
182 std::string::size_type delim;
184 // chop ss into terms from left to right
186 bool imaginary = false;
187 delim = ss.find_first_of(std::string("+-"),1);
188 // Do we have an exponent marker like "31.415E-1"? If so, hop on!
189 if ((delim != std::string::npos) && (ss.at(delim-1) == 'E'))
190 delim = ss.find_first_of(std::string("+-"),delim+1);
191 term = ss.substr(0,delim);
192 if (delim != std::string::npos)
193 ss = ss.substr(delim);
194 // is the term imaginary?
195 if (term.find("I") != std::string::npos) {
197 term = term.replace(term.find("I"),1,"");
199 if (term.find("*") != std::string::npos)
200 term = term.replace(term.find("*"),1,"");
201 // correct for trivial +/-I without explicit factor on I:
202 if (term.size() == 1)
206 if (term.find(".") != std::string::npos) {
207 // CLN's short type cl_SF is not very useful within the GiNaC
208 // framework where we are mainly interested in the arbitrary
209 // precision type cl_LF. Hence we go straight to the construction
210 // of generic floats. In order to create them we have to convert
211 // our own floating point notation used for output and construction
212 // from char * to CLN's generic notation:
213 // 3.14 --> 3.14e0_<Digits>
214 // 31.4E-1 --> 31.4e-1_<Digits>
216 // No exponent marker? Let's add a trivial one.
217 if (term.find("E") == std::string::npos)
220 term = term.replace(term.find("E"),1,"e");
221 // append _<Digits> to term
222 #if defined(HAVE_SSTREAM)
223 std::ostringstream buf;
224 buf << unsigned(Digits) << std::ends;
225 term += "_" + buf.str();
228 std::ostrstream(buf,sizeof(buf)) << unsigned(Digits) << std::ends;
229 term += "_" + std::string(buf);
231 // construct float using cln::cl_F(const char *) ctor.
233 ctorval = ctorval + cln::complex(cln::cl_I(0),cln::cl_F(term.c_str()));
235 ctorval = ctorval + cln::cl_F(term.c_str());
237 // not a floating point number...
239 ctorval = ctorval + cln::complex(cln::cl_I(0),cln::cl_R(term.c_str()));
241 ctorval = ctorval + cln::cl_R(term.c_str());
243 } while(delim != std::string::npos);
245 setflag(status_flags::evaluated | status_flags::expanded);
249 /** Ctor from CLN types. This is for the initiated user or internal use
251 numeric::numeric(const cln::cl_N &z) : basic(TINFO_numeric)
253 debugmsg("numeric ctor from cl_N", LOGLEVEL_CONSTRUCT);
255 setflag(status_flags::evaluated | status_flags::expanded);
262 numeric::numeric(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst)
264 debugmsg("numeric ctor from archive_node", LOGLEVEL_CONSTRUCT);
265 cln::cl_N ctorval = 0;
267 // Read number as string
269 if (n.find_string("number", str)) {
271 std::istringstream s(str);
273 std::istrstream s(str.c_str(), str.size() + 1);
275 cln::cl_idecoded_float re, im;
279 case 'R': // Integer-decoded real number
280 s >> re.sign >> re.mantissa >> re.exponent;
281 ctorval = re.sign * re.mantissa * cln::expt(cln::cl_float(2.0, cln::default_float_format), re.exponent);
283 case 'C': // Integer-decoded complex number
284 s >> re.sign >> re.mantissa >> re.exponent;
285 s >> im.sign >> im.mantissa >> im.exponent;
286 ctorval = cln::complex(re.sign * re.mantissa * cln::expt(cln::cl_float(2.0, cln::default_float_format), re.exponent),
287 im.sign * im.mantissa * cln::expt(cln::cl_float(2.0, cln::default_float_format), im.exponent));
289 default: // Ordinary number
296 setflag(status_flags::evaluated | status_flags::expanded);
299 void numeric::archive(archive_node &n) const
301 inherited::archive(n);
303 // Write number as string
305 std::ostringstream s;
308 std::ostrstream s(buf, 1024);
310 if (this->is_crational())
311 s << cln::the<cln::cl_N>(value);
313 // Non-rational numbers are written in an integer-decoded format
314 // to preserve the precision
315 if (this->is_real()) {
316 cln::cl_idecoded_float re = cln::integer_decode_float(cln::the<cln::cl_F>(value));
318 s << re.sign << " " << re.mantissa << " " << re.exponent;
320 cln::cl_idecoded_float re = cln::integer_decode_float(cln::the<cln::cl_F>(cln::realpart(cln::the<cln::cl_N>(value))));
321 cln::cl_idecoded_float im = cln::integer_decode_float(cln::the<cln::cl_F>(cln::imagpart(cln::the<cln::cl_N>(value))));
323 s << re.sign << " " << re.mantissa << " " << re.exponent << " ";
324 s << im.sign << " " << im.mantissa << " " << im.exponent;
328 n.add_string("number", s.str());
331 std::string str(buf);
332 n.add_string("number", str);
336 DEFAULT_UNARCHIVE(numeric)
339 // functions overriding virtual functions from bases classes
342 /** Helper function to print a real number in a nicer way than is CLN's
343 * default. Instead of printing 42.0L0 this just prints 42.0 to ostream os
344 * and instead of 3.99168L7 it prints 3.99168E7. This is fine in GiNaC as
345 * long as it only uses cl_LF and no other floating point types that we might
346 * want to visibly distinguish from cl_LF.
348 * @see numeric::print() */
349 static void print_real_number(std::ostream &os, const cln::cl_R &num)
351 cln::cl_print_flags ourflags;
352 if (cln::instanceof(num, cln::cl_RA_ring)) {
353 // case 1: integer or rational, nothing special to do:
354 cln::print_real(os, ourflags, num);
357 // make CLN believe this number has default_float_format, so it prints
358 // 'E' as exponent marker instead of 'L':
359 ourflags.default_float_format = cln::float_format(cln::the<cln::cl_F>(num));
360 cln::print_real(os, ourflags, num);
365 /** This method adds to the output so it blends more consistently together
366 * with the other routines and produces something compatible to ginsh input.
368 * @see print_real_number() */
369 void numeric::print(const print_context & c, unsigned level) const
371 debugmsg("numeric print", LOGLEVEL_PRINT);
373 if (is_a<print_tree>(c)) {
375 c.s << std::string(level, ' ') << cln::the<cln::cl_N>(value)
376 << " (" << class_name() << ")"
377 << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
380 } else if (is_a<print_csrc>(c)) {
382 std::ios::fmtflags oldflags = c.s.flags();
383 c.s.setf(std::ios::scientific);
384 if (this->is_rational() && !this->is_integer()) {
385 if (compare(_num0()) > 0) {
387 if (is_a<print_csrc_cl_N>(c))
388 c.s << "cln::cl_F(\"" << numer().evalf() << "\")";
390 c.s << numer().to_double();
393 if (is_a<print_csrc_cl_N>(c))
394 c.s << "cln::cl_F(\"" << -numer().evalf() << "\")";
396 c.s << -numer().to_double();
399 if (is_a<print_csrc_cl_N>(c))
400 c.s << "cln::cl_F(\"" << denom().evalf() << "\")";
402 c.s << denom().to_double();
405 if (is_a<print_csrc_cl_N>(c))
406 c.s << "cln::cl_F(\"" << evalf() << "\")";
413 const std::string par_open = is_a<print_latex>(c) ? "{(" : "(";
414 const std::string par_close = is_a<print_latex>(c) ? ")}" : ")";
415 const std::string imag_sym = is_a<print_latex>(c) ? "i" : "I";
416 const std::string mul_sym = is_a<print_latex>(c) ? " " : "*";
417 const cln::cl_R r = cln::realpart(cln::the<cln::cl_N>(value));
418 const cln::cl_R i = cln::imagpart(cln::the<cln::cl_N>(value));
420 // case 1, real: x or -x
421 if ((precedence() <= level) && (!this->is_nonneg_integer())) {
423 print_real_number(c.s, r);
426 print_real_number(c.s, r);
430 // case 2, imaginary: y*I or -y*I
431 if ((precedence() <= level) && (i < 0)) {
433 c.s << par_open+imag_sym+par_close;
436 print_real_number(c.s, i);
437 c.s << mul_sym+imag_sym+par_close;
444 c.s << "-" << imag_sym;
446 print_real_number(c.s, i);
447 c.s << mul_sym+imag_sym;
452 // case 3, complex: x+y*I or x-y*I or -x+y*I or -x-y*I
453 if (precedence() <= level)
455 print_real_number(c.s, r);
460 print_real_number(c.s, i);
461 c.s << mul_sym+imag_sym;
468 print_real_number(c.s, i);
469 c.s << mul_sym+imag_sym;
472 if (precedence() <= level)
479 bool numeric::info(unsigned inf) const
482 case info_flags::numeric:
483 case info_flags::polynomial:
484 case info_flags::rational_function:
486 case info_flags::real:
488 case info_flags::rational:
489 case info_flags::rational_polynomial:
490 return is_rational();
491 case info_flags::crational:
492 case info_flags::crational_polynomial:
493 return is_crational();
494 case info_flags::integer:
495 case info_flags::integer_polynomial:
497 case info_flags::cinteger:
498 case info_flags::cinteger_polynomial:
499 return is_cinteger();
500 case info_flags::positive:
501 return is_positive();
502 case info_flags::negative:
503 return is_negative();
504 case info_flags::nonnegative:
505 return !is_negative();
506 case info_flags::posint:
507 return is_pos_integer();
508 case info_flags::negint:
509 return is_integer() && is_negative();
510 case info_flags::nonnegint:
511 return is_nonneg_integer();
512 case info_flags::even:
514 case info_flags::odd:
516 case info_flags::prime:
518 case info_flags::algebraic:
524 /** Disassemble real part and imaginary part to scan for the occurrence of a
525 * single number. Also handles the imaginary unit. It ignores the sign on
526 * both this and the argument, which may lead to what might appear as funny
527 * results: (2+I).has(-2) -> true. But this is consistent, since we also
528 * would like to have (-2+I).has(2) -> true and we want to think about the
529 * sign as a multiplicative factor. */
530 bool numeric::has(const ex &other) const
532 if (!is_exactly_of_type(*other.bp, numeric))
534 const numeric &o = static_cast<numeric &>(const_cast<basic &>(*other.bp));
535 if (this->is_equal(o) || this->is_equal(-o))
537 if (o.imag().is_zero()) // e.g. scan for 3 in -3*I
538 return (this->real().is_equal(o) || this->imag().is_equal(o) ||
539 this->real().is_equal(-o) || this->imag().is_equal(-o));
541 if (o.is_equal(I)) // e.g scan for I in 42*I
542 return !this->is_real();
543 if (o.real().is_zero()) // e.g. scan for 2*I in 2*I+1
544 return (this->real().has(o*I) || this->imag().has(o*I) ||
545 this->real().has(-o*I) || this->imag().has(-o*I));
551 /** Evaluation of numbers doesn't do anything at all. */
552 ex numeric::eval(int level) const
554 // Warning: if this is ever gonna do something, the ex ctors from all kinds
555 // of numbers should be checking for status_flags::evaluated.
560 /** Cast numeric into a floating-point object. For example exact numeric(1) is
561 * returned as a 1.0000000000000000000000 and so on according to how Digits is
562 * currently set. In case the object already was a floating point number the
563 * precision is trimmed to match the currently set default.
565 * @param level ignored, only needed for overriding basic::evalf.
566 * @return an ex-handle to a numeric. */
567 ex numeric::evalf(int level) const
569 // level can safely be discarded for numeric objects.
570 return numeric(cln::cl_float(1.0, cln::default_float_format) *
571 (cln::the<cln::cl_N>(value)));
576 int numeric::compare_same_type(const basic &other) const
578 GINAC_ASSERT(is_exactly_of_type(other, numeric));
579 const numeric &o = static_cast<numeric &>(const_cast<basic &>(other));
581 return this->compare(o);
585 bool numeric::is_equal_same_type(const basic &other) const
587 GINAC_ASSERT(is_exactly_of_type(other,numeric));
588 const numeric *o = static_cast<const numeric *>(&other);
590 return this->is_equal(*o);
594 unsigned numeric::calchash(void) const
596 // Use CLN's hashcode. Warning: It depends only on the number's value, not
597 // its type or precision (i.e. a true equivalence relation on numbers). As
598 // a consequence, 3 and 3.0 share the same hashvalue.
599 setflag(status_flags::hash_calculated);
600 return (hashvalue = cln::equal_hashcode(cln::the<cln::cl_N>(value)) | 0x80000000U);
605 // new virtual functions which can be overridden by derived classes
611 // non-virtual functions in this class
616 /** Numerical addition method. Adds argument to *this and returns result as
617 * a numeric object. */
618 const numeric numeric::add(const numeric &other) const
620 // Efficiency shortcut: trap the neutral element by pointer.
621 static const numeric * _num0p = &_num0();
624 else if (&other==_num0p)
627 return numeric(cln::the<cln::cl_N>(value)+cln::the<cln::cl_N>(other.value));
631 /** Numerical subtraction method. Subtracts argument from *this and returns
632 * result as a numeric object. */
633 const numeric numeric::sub(const numeric &other) const
635 return numeric(cln::the<cln::cl_N>(value)-cln::the<cln::cl_N>(other.value));
639 /** Numerical multiplication method. Multiplies *this and argument and returns
640 * result as a numeric object. */
641 const numeric numeric::mul(const numeric &other) const
643 // Efficiency shortcut: trap the neutral element by pointer.
644 static const numeric * _num1p = &_num1();
647 else if (&other==_num1p)
650 return numeric(cln::the<cln::cl_N>(value)*cln::the<cln::cl_N>(other.value));
654 /** Numerical division method. Divides *this by argument and returns result as
657 * @exception overflow_error (division by zero) */
658 const numeric numeric::div(const numeric &other) const
660 if (cln::zerop(cln::the<cln::cl_N>(other.value)))
661 throw std::overflow_error("numeric::div(): division by zero");
662 return numeric(cln::the<cln::cl_N>(value)/cln::the<cln::cl_N>(other.value));
666 /** Numerical exponentiation. Raises *this to the power given as argument and
667 * returns result as a numeric object. */
668 const numeric numeric::power(const numeric &other) const
670 // Efficiency shortcut: trap the neutral exponent by pointer.
671 static const numeric * _num1p = &_num1();
675 if (cln::zerop(cln::the<cln::cl_N>(value))) {
676 if (cln::zerop(cln::the<cln::cl_N>(other.value)))
677 throw std::domain_error("numeric::eval(): pow(0,0) is undefined");
678 else if (cln::zerop(cln::realpart(cln::the<cln::cl_N>(other.value))))
679 throw std::domain_error("numeric::eval(): pow(0,I) is undefined");
680 else if (cln::minusp(cln::realpart(cln::the<cln::cl_N>(other.value))))
681 throw std::overflow_error("numeric::eval(): division by zero");
685 return numeric(cln::expt(cln::the<cln::cl_N>(value),cln::the<cln::cl_N>(other.value)));
689 const numeric &numeric::add_dyn(const numeric &other) const
691 // Efficiency shortcut: trap the neutral element by pointer.
692 static const numeric * _num0p = &_num0();
695 else if (&other==_num0p)
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 const numeric &numeric::sub_dyn(const numeric &other) const
705 return static_cast<const numeric &>((new numeric(cln::the<cln::cl_N>(value)-cln::the<cln::cl_N>(other.value)))->
706 setflag(status_flags::dynallocated));
710 const numeric &numeric::mul_dyn(const numeric &other) const
712 // Efficiency shortcut: trap the neutral element by pointer.
713 static const numeric * _num1p = &_num1();
716 else if (&other==_num1p)
719 return static_cast<const numeric &>((new numeric(cln::the<cln::cl_N>(value)*cln::the<cln::cl_N>(other.value)))->
720 setflag(status_flags::dynallocated));
724 const numeric &numeric::div_dyn(const numeric &other) const
726 if (cln::zerop(cln::the<cln::cl_N>(other.value)))
727 throw std::overflow_error("division by zero");
728 return static_cast<const numeric &>((new numeric(cln::the<cln::cl_N>(value)/cln::the<cln::cl_N>(other.value)))->
729 setflag(status_flags::dynallocated));
733 const numeric &numeric::power_dyn(const numeric &other) const
735 // Efficiency shortcut: trap the neutral exponent by pointer.
736 static const numeric * _num1p=&_num1();
740 if (cln::zerop(cln::the<cln::cl_N>(value))) {
741 if (cln::zerop(cln::the<cln::cl_N>(other.value)))
742 throw std::domain_error("numeric::eval(): pow(0,0) is undefined");
743 else if (cln::zerop(cln::realpart(cln::the<cln::cl_N>(other.value))))
744 throw std::domain_error("numeric::eval(): pow(0,I) is undefined");
745 else if (cln::minusp(cln::realpart(cln::the<cln::cl_N>(other.value))))
746 throw std::overflow_error("numeric::eval(): division by zero");
750 return static_cast<const numeric &>((new numeric(cln::expt(cln::the<cln::cl_N>(value),cln::the<cln::cl_N>(other.value))))->
751 setflag(status_flags::dynallocated));
755 const numeric &numeric::operator=(int i)
757 return operator=(numeric(i));
761 const numeric &numeric::operator=(unsigned int i)
763 return operator=(numeric(i));
767 const numeric &numeric::operator=(long i)
769 return operator=(numeric(i));
773 const numeric &numeric::operator=(unsigned long i)
775 return operator=(numeric(i));
779 const numeric &numeric::operator=(double d)
781 return operator=(numeric(d));
785 const numeric &numeric::operator=(const char * s)
787 return operator=(numeric(s));
791 /** Inverse of a number. */
792 const numeric numeric::inverse(void) const
794 if (cln::zerop(cln::the<cln::cl_N>(value)))
795 throw std::overflow_error("numeric::inverse(): division by zero");
796 return numeric(cln::recip(cln::the<cln::cl_N>(value)));
800 /** Return the complex half-plane (left or right) in which the number lies.
801 * csgn(x)==0 for x==0, csgn(x)==1 for Re(x)>0 or Re(x)=0 and Im(x)>0,
802 * csgn(x)==-1 for Re(x)<0 or Re(x)=0 and Im(x)<0.
804 * @see numeric::compare(const numeric &other) */
805 int numeric::csgn(void) const
807 if (cln::zerop(cln::the<cln::cl_N>(value)))
809 cln::cl_R r = cln::realpart(cln::the<cln::cl_N>(value));
810 if (!cln::zerop(r)) {
816 if (cln::plusp(cln::imagpart(cln::the<cln::cl_N>(value))))
824 /** This method establishes a canonical order on all numbers. For complex
825 * numbers this is not possible in a mathematically consistent way but we need
826 * to establish some order and it ought to be fast. So we simply define it
827 * to be compatible with our method csgn.
829 * @return csgn(*this-other)
830 * @see numeric::csgn(void) */
831 int numeric::compare(const numeric &other) const
833 // Comparing two real numbers?
834 if (cln::instanceof(value, cln::cl_R_ring) &&
835 cln::instanceof(other.value, cln::cl_R_ring))
836 // Yes, so just cln::compare them
837 return cln::compare(cln::the<cln::cl_R>(value), cln::the<cln::cl_R>(other.value));
839 // No, first cln::compare real parts...
840 cl_signean real_cmp = cln::compare(cln::realpart(cln::the<cln::cl_N>(value)), cln::realpart(cln::the<cln::cl_N>(other.value)));
843 // ...and then the imaginary parts.
844 return cln::compare(cln::imagpart(cln::the<cln::cl_N>(value)), cln::imagpart(cln::the<cln::cl_N>(other.value)));
849 bool numeric::is_equal(const numeric &other) const
851 return cln::equal(cln::the<cln::cl_N>(value),cln::the<cln::cl_N>(other.value));
855 /** True if object is zero. */
856 bool numeric::is_zero(void) const
858 return cln::zerop(cln::the<cln::cl_N>(value));
862 /** True if object is not complex and greater than zero. */
863 bool numeric::is_positive(void) const
866 return cln::plusp(cln::the<cln::cl_R>(value));
871 /** True if object is not complex and less than zero. */
872 bool numeric::is_negative(void) const
875 return cln::minusp(cln::the<cln::cl_R>(value));
880 /** True if object is a non-complex integer. */
881 bool numeric::is_integer(void) const
883 return cln::instanceof(value, cln::cl_I_ring);
887 /** True if object is an exact integer greater than zero. */
888 bool numeric::is_pos_integer(void) const
890 return (this->is_integer() && cln::plusp(cln::the<cln::cl_I>(value)));
894 /** True if object is an exact integer greater or equal zero. */
895 bool numeric::is_nonneg_integer(void) const
897 return (this->is_integer() && !cln::minusp(cln::the<cln::cl_I>(value)));
901 /** True if object is an exact even integer. */
902 bool numeric::is_even(void) const
904 return (this->is_integer() && cln::evenp(cln::the<cln::cl_I>(value)));
908 /** True if object is an exact odd integer. */
909 bool numeric::is_odd(void) const
911 return (this->is_integer() && cln::oddp(cln::the<cln::cl_I>(value)));
915 /** Probabilistic primality test.
917 * @return true if object is exact integer and prime. */
918 bool numeric::is_prime(void) const
920 return (this->is_integer() && cln::isprobprime(cln::the<cln::cl_I>(value)));
924 /** True if object is an exact rational number, may even be complex
925 * (denominator may be unity). */
926 bool numeric::is_rational(void) const
928 return cln::instanceof(value, cln::cl_RA_ring);
932 /** True if object is a real integer, rational or float (but not complex). */
933 bool numeric::is_real(void) const
935 return cln::instanceof(value, cln::cl_R_ring);
939 bool numeric::operator==(const numeric &other) const
941 return cln::equal(cln::the<cln::cl_N>(value), cln::the<cln::cl_N>(other.value));
945 bool numeric::operator!=(const numeric &other) const
947 return !cln::equal(cln::the<cln::cl_N>(value), cln::the<cln::cl_N>(other.value));
951 /** True if object is element of the domain of integers extended by I, i.e. is
952 * of the form a+b*I, where a and b are integers. */
953 bool numeric::is_cinteger(void) const
955 if (cln::instanceof(value, cln::cl_I_ring))
957 else if (!this->is_real()) { // complex case, handle n+m*I
958 if (cln::instanceof(cln::realpart(cln::the<cln::cl_N>(value)), cln::cl_I_ring) &&
959 cln::instanceof(cln::imagpart(cln::the<cln::cl_N>(value)), cln::cl_I_ring))
966 /** True if object is an exact rational number, may even be complex
967 * (denominator may be unity). */
968 bool numeric::is_crational(void) const
970 if (cln::instanceof(value, cln::cl_RA_ring))
972 else if (!this->is_real()) { // complex case, handle Q(i):
973 if (cln::instanceof(cln::realpart(cln::the<cln::cl_N>(value)), cln::cl_RA_ring) &&
974 cln::instanceof(cln::imagpart(cln::the<cln::cl_N>(value)), cln::cl_RA_ring))
981 /** Numerical comparison: less.
983 * @exception invalid_argument (complex inequality) */
984 bool numeric::operator<(const numeric &other) const
986 if (this->is_real() && other.is_real())
987 return (cln::the<cln::cl_R>(value) < cln::the<cln::cl_R>(other.value));
988 throw std::invalid_argument("numeric::operator<(): complex inequality");
992 /** Numerical comparison: less or equal.
994 * @exception invalid_argument (complex inequality) */
995 bool numeric::operator<=(const numeric &other) const
997 if (this->is_real() && other.is_real())
998 return (cln::the<cln::cl_R>(value) <= cln::the<cln::cl_R>(other.value));
999 throw std::invalid_argument("numeric::operator<=(): complex inequality");
1003 /** Numerical comparison: greater.
1005 * @exception invalid_argument (complex inequality) */
1006 bool numeric::operator>(const numeric &other) const
1008 if (this->is_real() && other.is_real())
1009 return (cln::the<cln::cl_R>(value) > cln::the<cln::cl_R>(other.value));
1010 throw std::invalid_argument("numeric::operator>(): complex inequality");
1014 /** Numerical comparison: greater or equal.
1016 * @exception invalid_argument (complex inequality) */
1017 bool numeric::operator>=(const numeric &other) const
1019 if (this->is_real() && other.is_real())
1020 return (cln::the<cln::cl_R>(value) >= cln::the<cln::cl_R>(other.value));
1021 throw std::invalid_argument("numeric::operator>=(): complex inequality");
1025 /** Converts numeric types to machine's int. You should check with
1026 * is_integer() if the number is really an integer before calling this method.
1027 * You may also consider checking the range first. */
1028 int numeric::to_int(void) const
1030 GINAC_ASSERT(this->is_integer());
1031 return cln::cl_I_to_int(cln::the<cln::cl_I>(value));
1035 /** Converts numeric types to machine's long. You should check with
1036 * is_integer() if the number is really an integer before calling this method.
1037 * You may also consider checking the range first. */
1038 long numeric::to_long(void) const
1040 GINAC_ASSERT(this->is_integer());
1041 return cln::cl_I_to_long(cln::the<cln::cl_I>(value));
1045 /** Converts numeric types to machine's double. You should check with is_real()
1046 * if the number is really not complex before calling this method. */
1047 double numeric::to_double(void) const
1049 GINAC_ASSERT(this->is_real());
1050 return cln::double_approx(cln::realpart(cln::the<cln::cl_N>(value)));
1054 /** Returns a new CLN object of type cl_N, representing the value of *this.
1055 * This method may be used when mixing GiNaC and CLN in one project.
1057 cln::cl_N numeric::to_cl_N(void) const
1059 return cln::cl_N(cln::the<cln::cl_N>(value));
1063 /** Real part of a number. */
1064 const numeric numeric::real(void) const
1066 return numeric(cln::realpart(cln::the<cln::cl_N>(value)));
1070 /** Imaginary part of a number. */
1071 const numeric numeric::imag(void) const
1073 return numeric(cln::imagpart(cln::the<cln::cl_N>(value)));
1077 /** Numerator. Computes the numerator of rational numbers, rationalized
1078 * numerator of complex if real and imaginary part are both rational numbers
1079 * (i.e numer(4/3+5/6*I) == 8+5*I), the number carrying the sign in all other
1081 const numeric numeric::numer(void) const
1083 if (this->is_integer())
1084 return numeric(*this);
1086 else if (cln::instanceof(value, cln::cl_RA_ring))
1087 return numeric(cln::numerator(cln::the<cln::cl_RA>(value)));
1089 else if (!this->is_real()) { // complex case, handle Q(i):
1090 const cln::cl_RA r = cln::the<cln::cl_RA>(cln::realpart(cln::the<cln::cl_N>(value)));
1091 const cln::cl_RA i = cln::the<cln::cl_RA>(cln::imagpart(cln::the<cln::cl_N>(value)));
1092 if (cln::instanceof(r, cln::cl_I_ring) && cln::instanceof(i, cln::cl_I_ring))
1093 return numeric(*this);
1094 if (cln::instanceof(r, cln::cl_I_ring) && cln::instanceof(i, cln::cl_RA_ring))
1095 return numeric(cln::complex(r*cln::denominator(i), cln::numerator(i)));
1096 if (cln::instanceof(r, cln::cl_RA_ring) && cln::instanceof(i, cln::cl_I_ring))
1097 return numeric(cln::complex(cln::numerator(r), i*cln::denominator(r)));
1098 if (cln::instanceof(r, cln::cl_RA_ring) && cln::instanceof(i, cln::cl_RA_ring)) {
1099 const cln::cl_I s = cln::lcm(cln::denominator(r), cln::denominator(i));
1100 return numeric(cln::complex(cln::numerator(r)*(cln::exquo(s,cln::denominator(r))),
1101 cln::numerator(i)*(cln::exquo(s,cln::denominator(i)))));
1104 // at least one float encountered
1105 return numeric(*this);
1109 /** Denominator. Computes the denominator of rational numbers, common integer
1110 * denominator of complex if real and imaginary part are both rational numbers
1111 * (i.e denom(4/3+5/6*I) == 6), one in all other cases. */
1112 const numeric numeric::denom(void) const
1114 if (this->is_integer())
1117 if (cln::instanceof(value, cln::cl_RA_ring))
1118 return numeric(cln::denominator(cln::the<cln::cl_RA>(value)));
1120 if (!this->is_real()) { // complex case, handle Q(i):
1121 const cln::cl_RA r = cln::the<cln::cl_RA>(cln::realpart(cln::the<cln::cl_N>(value)));
1122 const cln::cl_RA i = cln::the<cln::cl_RA>(cln::imagpart(cln::the<cln::cl_N>(value)));
1123 if (cln::instanceof(r, cln::cl_I_ring) && cln::instanceof(i, cln::cl_I_ring))
1125 if (cln::instanceof(r, cln::cl_I_ring) && cln::instanceof(i, cln::cl_RA_ring))
1126 return numeric(cln::denominator(i));
1127 if (cln::instanceof(r, cln::cl_RA_ring) && cln::instanceof(i, cln::cl_I_ring))
1128 return numeric(cln::denominator(r));
1129 if (cln::instanceof(r, cln::cl_RA_ring) && cln::instanceof(i, cln::cl_RA_ring))
1130 return numeric(cln::lcm(cln::denominator(r), cln::denominator(i)));
1132 // at least one float encountered
1137 /** Size in binary notation. For integers, this is the smallest n >= 0 such
1138 * that -2^n <= x < 2^n. If x > 0, this is the unique n > 0 such that
1139 * 2^(n-1) <= x < 2^n.
1141 * @return number of bits (excluding sign) needed to represent that number
1142 * in two's complement if it is an integer, 0 otherwise. */
1143 int numeric::int_length(void) const
1145 if (this->is_integer())
1146 return cln::integer_length(cln::the<cln::cl_I>(value));
1155 /** Imaginary unit. This is not a constant but a numeric since we are
1156 * natively handing complex numbers anyways, so in each expression containing
1157 * an I it is automatically eval'ed away anyhow. */
1158 const numeric I = numeric(cln::complex(cln::cl_I(0),cln::cl_I(1)));
1161 /** Exponential function.
1163 * @return arbitrary precision numerical exp(x). */
1164 const numeric exp(const numeric &x)
1166 return cln::exp(x.to_cl_N());
1170 /** Natural logarithm.
1172 * @param z complex number
1173 * @return arbitrary precision numerical log(x).
1174 * @exception pole_error("log(): logarithmic pole",0) */
1175 const numeric log(const numeric &z)
1178 throw pole_error("log(): logarithmic pole",0);
1179 return cln::log(z.to_cl_N());
1183 /** Numeric sine (trigonometric function).
1185 * @return arbitrary precision numerical sin(x). */
1186 const numeric sin(const numeric &x)
1188 return cln::sin(x.to_cl_N());
1192 /** Numeric cosine (trigonometric function).
1194 * @return arbitrary precision numerical cos(x). */
1195 const numeric cos(const numeric &x)
1197 return cln::cos(x.to_cl_N());
1201 /** Numeric tangent (trigonometric function).
1203 * @return arbitrary precision numerical tan(x). */
1204 const numeric tan(const numeric &x)
1206 return cln::tan(x.to_cl_N());
1210 /** Numeric inverse sine (trigonometric function).
1212 * @return arbitrary precision numerical asin(x). */
1213 const numeric asin(const numeric &x)
1215 return cln::asin(x.to_cl_N());
1219 /** Numeric inverse cosine (trigonometric function).
1221 * @return arbitrary precision numerical acos(x). */
1222 const numeric acos(const numeric &x)
1224 return cln::acos(x.to_cl_N());
1230 * @param z complex number
1232 * @exception pole_error("atan(): logarithmic pole",0) */
1233 const numeric atan(const numeric &x)
1236 x.real().is_zero() &&
1237 abs(x.imag()).is_equal(_num1()))
1238 throw pole_error("atan(): logarithmic pole",0);
1239 return cln::atan(x.to_cl_N());
1245 * @param x real number
1246 * @param y real number
1247 * @return atan(y/x) */
1248 const numeric atan(const numeric &y, const numeric &x)
1250 if (x.is_real() && y.is_real())
1251 return cln::atan(cln::the<cln::cl_R>(x.to_cl_N()),
1252 cln::the<cln::cl_R>(y.to_cl_N()));
1254 throw std::invalid_argument("atan(): complex argument");
1258 /** Numeric hyperbolic sine (trigonometric function).
1260 * @return arbitrary precision numerical sinh(x). */
1261 const numeric sinh(const numeric &x)
1263 return cln::sinh(x.to_cl_N());
1267 /** Numeric hyperbolic cosine (trigonometric function).
1269 * @return arbitrary precision numerical cosh(x). */
1270 const numeric cosh(const numeric &x)
1272 return cln::cosh(x.to_cl_N());
1276 /** Numeric hyperbolic tangent (trigonometric function).
1278 * @return arbitrary precision numerical tanh(x). */
1279 const numeric tanh(const numeric &x)
1281 return cln::tanh(x.to_cl_N());
1285 /** Numeric inverse hyperbolic sine (trigonometric function).
1287 * @return arbitrary precision numerical asinh(x). */
1288 const numeric asinh(const numeric &x)
1290 return cln::asinh(x.to_cl_N());
1294 /** Numeric inverse hyperbolic cosine (trigonometric function).
1296 * @return arbitrary precision numerical acosh(x). */
1297 const numeric acosh(const numeric &x)
1299 return cln::acosh(x.to_cl_N());
1303 /** Numeric inverse hyperbolic tangent (trigonometric function).
1305 * @return arbitrary precision numerical atanh(x). */
1306 const numeric atanh(const numeric &x)
1308 return cln::atanh(x.to_cl_N());
1312 /*static cln::cl_N Li2_series(const ::cl_N &x,
1313 const ::float_format_t &prec)
1315 // Note: argument must be in the unit circle
1316 // This is very inefficient unless we have fast floating point Bernoulli
1317 // numbers implemented!
1318 cln::cl_N c1 = -cln::log(1-x);
1320 // hard-wire the first two Bernoulli numbers
1321 cln::cl_N acc = c1 - cln::square(c1)/4;
1323 cln::cl_F pisq = cln::square(cln::cl_pi(prec)); // pi^2
1324 cln::cl_F piac = cln::cl_float(1, prec); // accumulator: pi^(2*i)
1326 c1 = cln::square(c1);
1330 aug = c2 * (*(bernoulli(numeric(2*i)).clnptr())) / cln::factorial(2*i+1);
1331 // 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));
1334 } while (acc != acc+aug);
1338 /** Numeric evaluation of Dilogarithm within circle of convergence (unit
1339 * circle) using a power series. */
1340 static cln::cl_N Li2_series(const cln::cl_N &x,
1341 const cln::float_format_t &prec)
1343 // Note: argument must be in the unit circle
1345 cln::cl_N num = cln::complex(cln::cl_float(1, prec), 0);
1350 den = den + i; // 1, 4, 9, 16, ...
1354 } while (acc != acc+aug);
1358 /** Folds Li2's argument inside a small rectangle to enhance convergence. */
1359 static cln::cl_N Li2_projection(const cln::cl_N &x,
1360 const cln::float_format_t &prec)
1362 const cln::cl_R re = cln::realpart(x);
1363 const cln::cl_R im = cln::imagpart(x);
1364 if (re > cln::cl_F(".5"))
1365 // zeta(2) - Li2(1-x) - log(x)*log(1-x)
1367 - Li2_series(1-x, prec)
1368 - cln::log(x)*cln::log(1-x));
1369 if ((re <= 0 && cln::abs(im) > cln::cl_F(".75")) || (re < cln::cl_F("-.5")))
1370 // -log(1-x)^2 / 2 - Li2(x/(x-1))
1371 return(- cln::square(cln::log(1-x))/2
1372 - Li2_series(x/(x-1), prec));
1373 if (re > 0 && cln::abs(im) > cln::cl_LF(".75"))
1374 // Li2(x^2)/2 - Li2(-x)
1375 return(Li2_projection(cln::square(x), prec)/2
1376 - Li2_projection(-x, prec));
1377 return Li2_series(x, prec);
1380 /** Numeric evaluation of Dilogarithm. The domain is the entire complex plane,
1381 * the branch cut lies along the positive real axis, starting at 1 and
1382 * continuous with quadrant IV.
1384 * @return arbitrary precision numerical Li2(x). */
1385 const numeric Li2(const numeric &x)
1390 // what is the desired float format?
1391 // first guess: default format
1392 cln::float_format_t prec = cln::default_float_format;
1393 const cln::cl_N value = x.to_cl_N();
1394 // second guess: the argument's format
1395 if (!x.real().is_rational())
1396 prec = cln::float_format(cln::the<cln::cl_F>(cln::realpart(value)));
1397 else if (!x.imag().is_rational())
1398 prec = cln::float_format(cln::the<cln::cl_F>(cln::imagpart(value)));
1400 if (cln::the<cln::cl_N>(value)==1) // may cause trouble with log(1-x)
1401 return cln::zeta(2, prec);
1403 if (cln::abs(value) > 1)
1404 // -log(-x)^2 / 2 - zeta(2) - Li2(1/x)
1405 return(- cln::square(cln::log(-value))/2
1406 - cln::zeta(2, prec)
1407 - Li2_projection(cln::recip(value), prec));
1409 return Li2_projection(x.to_cl_N(), prec);
1413 /** Numeric evaluation of Riemann's Zeta function. Currently works only for
1414 * integer arguments. */
1415 const numeric zeta(const numeric &x)
1417 // A dirty hack to allow for things like zeta(3.0), since CLN currently
1418 // only knows about integer arguments and zeta(3).evalf() automatically
1419 // cascades down to zeta(3.0).evalf(). The trick is to rely on 3.0-3
1420 // being an exact zero for CLN, which can be tested and then we can just
1421 // pass the number casted to an int:
1423 const int aux = (int)(cln::double_approx(cln::the<cln::cl_R>(x.to_cl_N())));
1424 if (cln::zerop(x.to_cl_N()-aux))
1425 return cln::zeta(aux);
1427 std::clog << "zeta(" << x
1428 << "): Does anybody know a good way to calculate this numerically?"
1434 /** The Gamma function.
1435 * This is only a stub! */
1436 const numeric lgamma(const numeric &x)
1438 std::clog << "lgamma(" << x
1439 << "): Does anybody know a good way to calculate this numerically?"
1443 const numeric tgamma(const numeric &x)
1445 std::clog << "tgamma(" << x
1446 << "): Does anybody know a good way to calculate this numerically?"
1452 /** The psi function (aka polygamma function).
1453 * This is only a stub! */
1454 const numeric psi(const numeric &x)
1456 std::clog << "psi(" << x
1457 << "): Does anybody know a good way to calculate this numerically?"
1463 /** The psi functions (aka polygamma functions).
1464 * This is only a stub! */
1465 const numeric psi(const numeric &n, const numeric &x)
1467 std::clog << "psi(" << n << "," << x
1468 << "): Does anybody know a good way to calculate this numerically?"
1474 /** Factorial combinatorial function.
1476 * @param n integer argument >= 0
1477 * @exception range_error (argument must be integer >= 0) */
1478 const numeric factorial(const numeric &n)
1480 if (!n.is_nonneg_integer())
1481 throw std::range_error("numeric::factorial(): argument must be integer >= 0");
1482 return numeric(cln::factorial(n.to_int()));
1486 /** The double factorial combinatorial function. (Scarcely used, but still
1487 * useful in cases, like for exact results of tgamma(n+1/2) for instance.)
1489 * @param n integer argument >= -1
1490 * @return n!! == n * (n-2) * (n-4) * ... * ({1|2}) with 0!! == (-1)!! == 1
1491 * @exception range_error (argument must be integer >= -1) */
1492 const numeric doublefactorial(const numeric &n)
1494 if (n.is_equal(_num_1()))
1497 if (!n.is_nonneg_integer())
1498 throw std::range_error("numeric::doublefactorial(): argument must be integer >= -1");
1500 return numeric(cln::doublefactorial(n.to_int()));
1504 /** The Binomial coefficients. It computes the binomial coefficients. For
1505 * integer n and k and positive n this is the number of ways of choosing k
1506 * objects from n distinct objects. If n is negative, the formula
1507 * binomial(n,k) == (-1)^k*binomial(k-n-1,k) is used to compute the result. */
1508 const numeric binomial(const numeric &n, const numeric &k)
1510 if (n.is_integer() && k.is_integer()) {
1511 if (n.is_nonneg_integer()) {
1512 if (k.compare(n)!=1 && k.compare(_num0())!=-1)
1513 return numeric(cln::binomial(n.to_int(),k.to_int()));
1517 return _num_1().power(k)*binomial(k-n-_num1(),k);
1521 // should really be gamma(n+1)/gamma(r+1)/gamma(n-r+1) or a suitable limit
1522 throw std::range_error("numeric::binomial(): don´t know how to evaluate that.");
1526 /** Bernoulli number. The nth Bernoulli number is the coefficient of x^n/n!
1527 * in the expansion of the function x/(e^x-1).
1529 * @return the nth Bernoulli number (a rational number).
1530 * @exception range_error (argument must be integer >= 0) */
1531 const numeric bernoulli(const numeric &nn)
1533 if (!nn.is_integer() || nn.is_negative())
1534 throw std::range_error("numeric::bernoulli(): argument must be integer >= 0");
1538 // The Bernoulli numbers are rational numbers that may be computed using
1541 // B_n = - 1/(n+1) * sum_{k=0}^{n-1}(binomial(n+1,k)*B_k)
1543 // with B(0) = 1. Since the n'th Bernoulli number depends on all the
1544 // previous ones, the computation is necessarily very expensive. There are
1545 // several other ways of computing them, a particularly good one being
1549 // for (unsigned i=0; i<n; i++) {
1550 // c = exquo(c*(i-n),(i+2));
1551 // Bern = Bern + c*s/(i+2);
1552 // s = s + expt_pos(cl_I(i+2),n);
1556 // But if somebody works with the n'th Bernoulli number she is likely to
1557 // also need all previous Bernoulli numbers. So we need a complete remember
1558 // table and above divide and conquer algorithm is not suited to build one
1559 // up. The code below is adapted from Pari's function bernvec().
1561 // (There is an interesting relation with the tangent polynomials described
1562 // in `Concrete Mathematics', which leads to a program twice as fast as our
1563 // implementation below, but it requires storing one such polynomial in
1564 // addition to the remember table. This doubles the memory footprint so
1565 // we don't use it.)
1567 // the special cases not covered by the algorithm below
1568 if (nn.is_equal(_num1()))
1573 // store nonvanishing Bernoulli numbers here
1574 static std::vector< cln::cl_RA > results;
1575 static int highest_result = 0;
1576 // algorithm not applicable to B(0), so just store it
1577 if (results.size()==0)
1578 results.push_back(cln::cl_RA(1));
1580 int n = nn.to_long();
1581 for (int i=highest_result; i<n/2; ++i) {
1587 for (int j=i; j>0; --j) {
1588 B = cln::cl_I(n*m) * (B+results[j]) / (d1*d2);
1594 B = (1 - ((B+1)/(2*i+3))) / (cln::cl_I(1)<<(2*i+2));
1595 results.push_back(B);
1598 return results[n/2];
1602 /** Fibonacci number. The nth Fibonacci number F(n) is defined by the
1603 * recurrence formula F(n)==F(n-1)+F(n-2) with F(0)==0 and F(1)==1.
1605 * @param n an integer
1606 * @return the nth Fibonacci number F(n) (an integer number)
1607 * @exception range_error (argument must be an integer) */
1608 const numeric fibonacci(const numeric &n)
1610 if (!n.is_integer())
1611 throw std::range_error("numeric::fibonacci(): argument must be integer");
1614 // The following addition formula holds:
1616 // F(n+m) = F(m-1)*F(n) + F(m)*F(n+1) for m >= 1, n >= 0.
1618 // (Proof: For fixed m, the LHS and the RHS satisfy the same recurrence
1619 // w.r.t. n, and the initial values (n=0, n=1) agree. Hence all values
1621 // Replace m by m+1:
1622 // F(n+m+1) = F(m)*F(n) + F(m+1)*F(n+1) for m >= 0, n >= 0
1623 // Now put in m = n, to get
1624 // F(2n) = (F(n+1)-F(n))*F(n) + F(n)*F(n+1) = F(n)*(2*F(n+1) - F(n))
1625 // F(2n+1) = F(n)^2 + F(n+1)^2
1627 // F(2n+2) = F(n+1)*(2*F(n) + F(n+1))
1630 if (n.is_negative())
1632 return -fibonacci(-n);
1634 return fibonacci(-n);
1638 cln::cl_I m = cln::the<cln::cl_I>(n.to_cl_N()) >> 1L; // floor(n/2);
1639 for (uintL bit=cln::integer_length(m); bit>0; --bit) {
1640 // Since a squaring is cheaper than a multiplication, better use
1641 // three squarings instead of one multiplication and two squarings.
1642 cln::cl_I u2 = cln::square(u);
1643 cln::cl_I v2 = cln::square(v);
1644 if (cln::logbitp(bit-1, m)) {
1645 v = cln::square(u + v) - u2;
1648 u = v2 - cln::square(v - u);
1653 // Here we don't use the squaring formula because one multiplication
1654 // is cheaper than two squarings.
1655 return u * ((v << 1) - u);
1657 return cln::square(u) + cln::square(v);
1661 /** Absolute value. */
1662 const numeric abs(const numeric& x)
1664 return cln::abs(x.to_cl_N());
1668 /** Modulus (in positive representation).
1669 * In general, mod(a,b) has the sign of b or is zero, and rem(a,b) has the
1670 * sign of a or is zero. This is different from Maple's modp, where the sign
1671 * of b is ignored. It is in agreement with Mathematica's Mod.
1673 * @return a mod b in the range [0,abs(b)-1] with sign of b if both are
1674 * integer, 0 otherwise. */
1675 const numeric mod(const numeric &a, const numeric &b)
1677 if (a.is_integer() && b.is_integer())
1678 return cln::mod(cln::the<cln::cl_I>(a.to_cl_N()),
1679 cln::the<cln::cl_I>(b.to_cl_N()));
1685 /** Modulus (in symmetric representation).
1686 * Equivalent to Maple's mods.
1688 * @return a mod b in the range [-iquo(abs(m)-1,2), iquo(abs(m),2)]. */
1689 const numeric smod(const numeric &a, const numeric &b)
1691 if (a.is_integer() && b.is_integer()) {
1692 const cln::cl_I b2 = cln::ceiling1(cln::the<cln::cl_I>(b.to_cl_N()) >> 1) - 1;
1693 return cln::mod(cln::the<cln::cl_I>(a.to_cl_N()) + b2,
1694 cln::the<cln::cl_I>(b.to_cl_N())) - b2;
1700 /** Numeric integer remainder.
1701 * Equivalent to Maple's irem(a,b) as far as sign conventions are concerned.
1702 * In general, mod(a,b) has the sign of b or is zero, and irem(a,b) has the
1703 * sign of a or is zero.
1705 * @return remainder of a/b if both are integer, 0 otherwise. */
1706 const numeric irem(const numeric &a, const numeric &b)
1708 if (a.is_integer() && b.is_integer())
1709 return cln::rem(cln::the<cln::cl_I>(a.to_cl_N()),
1710 cln::the<cln::cl_I>(b.to_cl_N()));
1716 /** Numeric integer remainder.
1717 * Equivalent to Maple's irem(a,b,'q') it obeyes the relation
1718 * irem(a,b,q) == a - q*b. In general, mod(a,b) has the sign of b or is zero,
1719 * and irem(a,b) has the sign of a or is zero.
1721 * @return remainder of a/b and quotient stored in q if both are integer,
1723 const numeric irem(const numeric &a, const numeric &b, numeric &q)
1725 if (a.is_integer() && b.is_integer()) {
1726 const cln::cl_I_div_t rem_quo = cln::truncate2(cln::the<cln::cl_I>(a.to_cl_N()),
1727 cln::the<cln::cl_I>(b.to_cl_N()));
1728 q = rem_quo.quotient;
1729 return rem_quo.remainder;
1737 /** Numeric integer quotient.
1738 * Equivalent to Maple's iquo as far as sign conventions are concerned.
1740 * @return truncated quotient of a/b if both are integer, 0 otherwise. */
1741 const numeric iquo(const numeric &a, const numeric &b)
1743 if (a.is_integer() && b.is_integer())
1744 return cln::truncate1(cln::the<cln::cl_I>(a.to_cl_N()),
1745 cln::the<cln::cl_I>(b.to_cl_N()));
1751 /** Numeric integer quotient.
1752 * Equivalent to Maple's iquo(a,b,'r') it obeyes the relation
1753 * r == a - iquo(a,b,r)*b.
1755 * @return truncated quotient of a/b and remainder stored in r if both are
1756 * integer, 0 otherwise. */
1757 const numeric iquo(const numeric &a, const numeric &b, numeric &r)
1759 if (a.is_integer() && b.is_integer()) {
1760 const cln::cl_I_div_t rem_quo = cln::truncate2(cln::the<cln::cl_I>(a.to_cl_N()),
1761 cln::the<cln::cl_I>(b.to_cl_N()));
1762 r = rem_quo.remainder;
1763 return rem_quo.quotient;
1771 /** Greatest Common Divisor.
1773 * @return The GCD of two numbers if both are integer, a numerical 1
1774 * if they are not. */
1775 const numeric gcd(const numeric &a, const numeric &b)
1777 if (a.is_integer() && b.is_integer())
1778 return cln::gcd(cln::the<cln::cl_I>(a.to_cl_N()),
1779 cln::the<cln::cl_I>(b.to_cl_N()));
1785 /** Least Common Multiple.
1787 * @return The LCM of two numbers if both are integer, the product of those
1788 * two numbers if they are not. */
1789 const numeric lcm(const numeric &a, const numeric &b)
1791 if (a.is_integer() && b.is_integer())
1792 return cln::lcm(cln::the<cln::cl_I>(a.to_cl_N()),
1793 cln::the<cln::cl_I>(b.to_cl_N()));
1799 /** Numeric square root.
1800 * If possible, sqrt(z) should respect squares of exact numbers, i.e. sqrt(4)
1801 * should return integer 2.
1803 * @param z numeric argument
1804 * @return square root of z. Branch cut along negative real axis, the negative
1805 * real axis itself where imag(z)==0 and real(z)<0 belongs to the upper part
1806 * where imag(z)>0. */
1807 const numeric sqrt(const numeric &z)
1809 return cln::sqrt(z.to_cl_N());
1813 /** Integer numeric square root. */
1814 const numeric isqrt(const numeric &x)
1816 if (x.is_integer()) {
1818 cln::isqrt(cln::the<cln::cl_I>(x.to_cl_N()), &root);
1825 /** Floating point evaluation of Archimedes' constant Pi. */
1828 return numeric(cln::pi(cln::default_float_format));
1832 /** Floating point evaluation of Euler's constant gamma. */
1835 return numeric(cln::eulerconst(cln::default_float_format));
1839 /** Floating point evaluation of Catalan's constant. */
1840 ex CatalanEvalf(void)
1842 return numeric(cln::catalanconst(cln::default_float_format));
1846 /** _numeric_digits default ctor, checking for singleton invariance. */
1847 _numeric_digits::_numeric_digits()
1850 // It initializes to 17 digits, because in CLN float_format(17) turns out
1851 // to be 61 (<64) while float_format(18)=65. The reason is we want to
1852 // have a cl_LF instead of cl_SF, cl_FF or cl_DF.
1854 throw(std::runtime_error("I told you not to do instantiate me!"));
1856 cln::default_float_format = cln::float_format(17);
1860 /** Assign a native long to global Digits object. */
1861 _numeric_digits& _numeric_digits::operator=(long prec)
1864 cln::default_float_format = cln::float_format(prec);
1869 /** Convert global Digits object to native type long. */
1870 _numeric_digits::operator long()
1872 // BTW, this is approx. unsigned(cln::default_float_format*0.301)-1
1873 return (long)digits;
1877 /** Append global Digits object to ostream. */
1878 void _numeric_digits::print(std::ostream &os) const
1880 debugmsg("_numeric_digits print", LOGLEVEL_PRINT);
1885 std::ostream& operator<<(std::ostream &os, const _numeric_digits &e)
1892 // static member variables
1897 bool _numeric_digits::too_late = false;
1900 /** Accuracy in decimal digits. Only object of this type! Can be set using
1901 * assignment from C++ unsigned ints and evaluated like any built-in type. */
1902 _numeric_digits Digits;
1904 } // namespace GiNaC