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
41 // CLN should pollute the global namespace as little as possible. Hence, we
42 // include most of it here and include only the part needed for properly
43 // declaring cln::cl_number in numeric.h. This can only be safely done in
44 // namespaced versions of CLN, i.e. version > 1.1.0. Also, we only need a
45 // subset of CLN, so we don't include the complete <cln/cln.h> but only the
47 #include <cln/output.h>
48 #include <cln/integer_io.h>
49 #include <cln/integer_ring.h>
50 #include <cln/rational_io.h>
51 #include <cln/rational_ring.h>
52 #include <cln/lfloat_class.h>
53 #include <cln/lfloat_io.h>
54 #include <cln/real_io.h>
55 #include <cln/real_ring.h>
56 #include <cln/complex_io.h>
57 #include <cln/complex_ring.h>
58 #include <cln/numtheory.h>
62 GINAC_IMPLEMENT_REGISTERED_CLASS(numeric, basic)
65 // default ctor, dtor, copy ctor, assignment operator and helpers
68 /** default ctor. Numerically it initializes to an integer zero. */
69 numeric::numeric() : basic(TINFO_numeric)
72 setflag(status_flags::evaluated | status_flags::expanded);
75 void numeric::copy(const numeric &other)
77 inherited::copy(other);
81 DEFAULT_DESTROY(numeric)
89 numeric::numeric(int i) : basic(TINFO_numeric)
91 // Not the whole int-range is available if we don't cast to long
92 // first. This is due to the behaviour of the cl_I-ctor, which
93 // emphasizes efficiency. However, if the integer is small enough,
94 // i.e. satisfies cl_immediate_p(), we save space and dereferences by
95 // using an immediate type:
96 if (cln::cl_immediate_p(i))
99 value = cln::cl_I((long) i);
100 setflag(status_flags::evaluated | status_flags::expanded);
104 numeric::numeric(unsigned int i) : basic(TINFO_numeric)
106 // Not the whole uint-range is available if we don't cast to ulong
107 // first. This is due to the behaviour of the cl_I-ctor, which
108 // emphasizes efficiency. However, if the integer is small enough,
109 // i.e. satisfies cl_immediate_p(), we save space and dereferences by
110 // using an immediate type:
111 if (cln::cl_immediate_p(i))
112 value = cln::cl_I(i);
114 value = cln::cl_I((unsigned long) i);
115 setflag(status_flags::evaluated | status_flags::expanded);
119 numeric::numeric(long i) : basic(TINFO_numeric)
121 value = cln::cl_I(i);
122 setflag(status_flags::evaluated | status_flags::expanded);
126 numeric::numeric(unsigned long i) : basic(TINFO_numeric)
128 value = cln::cl_I(i);
129 setflag(status_flags::evaluated | status_flags::expanded);
132 /** Ctor for rational numerics a/b.
134 * @exception overflow_error (division by zero) */
135 numeric::numeric(long numer, long denom) : basic(TINFO_numeric)
138 throw std::overflow_error("division by zero");
139 value = cln::cl_I(numer) / cln::cl_I(denom);
140 setflag(status_flags::evaluated | status_flags::expanded);
144 numeric::numeric(double d) : basic(TINFO_numeric)
146 // We really want to explicitly use the type cl_LF instead of the
147 // more general cl_F, since that would give us a cl_DF only which
148 // will not be promoted to cl_LF if overflow occurs:
149 value = cln::cl_float(d, cln::default_float_format);
150 setflag(status_flags::evaluated | status_flags::expanded);
154 /** ctor from C-style string. It also accepts complex numbers in GiNaC
155 * notation like "2+5*I". */
156 numeric::numeric(const char *s) : basic(TINFO_numeric)
158 cln::cl_N ctorval = 0;
159 // parse complex numbers (functional but not completely safe, unfortunately
160 // std::string does not understand regexpese):
161 // ss should represent a simple sum like 2+5*I
163 std::string::size_type delim;
165 // make this implementation safe by adding explicit sign
166 if (ss.at(0) != '+' && ss.at(0) != '-' && ss.at(0) != '#')
169 // We use 'E' as exponent marker in the output, but some people insist on
170 // writing 'e' at input, so let's substitute them right at the beginning:
171 while ((delim = ss.find('e'))!=std::string::npos)
172 ss = ss.replace(delim,1,'E');
176 // chop ss into terms from left to right
178 bool imaginary = false;
179 delim = ss.find_first_of(std::string("+-"),1);
180 // Do we have an exponent marker like "31.415E-1"? If so, hop on!
181 if (delim!=std::string::npos && ss.at(delim-1)=='E')
182 delim = ss.find_first_of(std::string("+-"),delim+1);
183 term = ss.substr(0,delim);
184 if (delim!=std::string::npos)
185 ss = ss.substr(delim);
186 // is the term imaginary?
187 if (term.find('I')!=std::string::npos) {
189 term = term.replace(term.find('I'),1,"");
191 if (term.find('*')!=std::string::npos)
192 term = term.replace(term.find('*'),1,"");
193 // correct for trivial +/-I without explicit factor on I:
198 if (term.find('.')!=std::string::npos || term.find('E')!=std::string::npos) {
199 // CLN's short type cl_SF is not very useful within the GiNaC
200 // framework where we are mainly interested in the arbitrary
201 // precision type cl_LF. Hence we go straight to the construction
202 // of generic floats. In order to create them we have to convert
203 // our own floating point notation used for output and construction
204 // from char * to CLN's generic notation:
205 // 3.14 --> 3.14e0_<Digits>
206 // 31.4E-1 --> 31.4e-1_<Digits>
208 // No exponent marker? Let's add a trivial one.
209 if (term.find('E')==std::string::npos)
212 term = term.replace(term.find('E'),1,'e');
213 // append _<Digits> to term
214 term += "_" + ToString((unsigned)Digits);
215 // construct float using cln::cl_F(const char *) ctor.
217 ctorval = ctorval + cln::complex(cln::cl_I(0),cln::cl_F(term.c_str()));
219 ctorval = ctorval + cln::cl_F(term.c_str());
221 // this is not a floating point number...
223 ctorval = ctorval + cln::complex(cln::cl_I(0),cln::cl_R(term.c_str()));
225 ctorval = ctorval + cln::cl_R(term.c_str());
227 } while (delim != std::string::npos);
229 setflag(status_flags::evaluated | status_flags::expanded);
233 /** Ctor from CLN types. This is for the initiated user or internal use
235 numeric::numeric(const cln::cl_N &z) : basic(TINFO_numeric)
238 setflag(status_flags::evaluated | status_flags::expanded);
245 numeric::numeric(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst)
247 cln::cl_N ctorval = 0;
249 // Read number as string
251 if (n.find_string("number", str)) {
252 std::istringstream s(str);
253 cln::cl_idecoded_float re, im;
257 case 'R': // Integer-decoded real number
258 s >> re.sign >> re.mantissa >> re.exponent;
259 ctorval = re.sign * re.mantissa * cln::expt(cln::cl_float(2.0, cln::default_float_format), re.exponent);
261 case 'C': // Integer-decoded complex number
262 s >> re.sign >> re.mantissa >> re.exponent;
263 s >> im.sign >> im.mantissa >> im.exponent;
264 ctorval = cln::complex(re.sign * re.mantissa * cln::expt(cln::cl_float(2.0, cln::default_float_format), re.exponent),
265 im.sign * im.mantissa * cln::expt(cln::cl_float(2.0, cln::default_float_format), im.exponent));
267 default: // Ordinary number
274 setflag(status_flags::evaluated | status_flags::expanded);
277 void numeric::archive(archive_node &n) const
279 inherited::archive(n);
281 // Write number as string
282 std::ostringstream s;
283 if (this->is_crational())
284 s << cln::the<cln::cl_N>(value);
286 // Non-rational numbers are written in an integer-decoded format
287 // to preserve the precision
288 if (this->is_real()) {
289 cln::cl_idecoded_float re = cln::integer_decode_float(cln::the<cln::cl_F>(value));
291 s << re.sign << " " << re.mantissa << " " << re.exponent;
293 cln::cl_idecoded_float re = cln::integer_decode_float(cln::the<cln::cl_F>(cln::realpart(cln::the<cln::cl_N>(value))));
294 cln::cl_idecoded_float im = cln::integer_decode_float(cln::the<cln::cl_F>(cln::imagpart(cln::the<cln::cl_N>(value))));
296 s << re.sign << " " << re.mantissa << " " << re.exponent << " ";
297 s << im.sign << " " << im.mantissa << " " << im.exponent;
300 n.add_string("number", s.str());
303 DEFAULT_UNARCHIVE(numeric)
306 // functions overriding virtual functions from base classes
309 /** Helper function to print a real number in a nicer way than is CLN's
310 * default. Instead of printing 42.0L0 this just prints 42.0 to ostream os
311 * and instead of 3.99168L7 it prints 3.99168E7. This is fine in GiNaC as
312 * long as it only uses cl_LF and no other floating point types that we might
313 * want to visibly distinguish from cl_LF.
315 * @see numeric::print() */
316 static void print_real_number(const print_context & c, const cln::cl_R &x)
318 cln::cl_print_flags ourflags;
319 if (cln::instanceof(x, cln::cl_RA_ring)) {
320 // case 1: integer or rational
321 if (cln::instanceof(x, cln::cl_I_ring) ||
322 !is_a<print_latex>(c)) {
323 cln::print_real(c.s, ourflags, x);
324 } else { // rational output in LaTeX context
326 cln::print_real(c.s, ourflags, cln::numerator(cln::the<cln::cl_RA>(x)));
328 cln::print_real(c.s, ourflags, cln::denominator(cln::the<cln::cl_RA>(x)));
333 // make CLN believe this number has default_float_format, so it prints
334 // 'E' as exponent marker instead of 'L':
335 ourflags.default_float_format = cln::float_format(cln::the<cln::cl_F>(x));
336 cln::print_real(c.s, ourflags, x);
340 /** This method adds to the output so it blends more consistently together
341 * with the other routines and produces something compatible to ginsh input.
343 * @see print_real_number() */
344 void numeric::print(const print_context & c, unsigned level) const
346 if (is_a<print_tree>(c)) {
348 c.s << std::string(level, ' ') << cln::the<cln::cl_N>(value)
349 << " (" << class_name() << ")"
350 << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
353 } else if (is_a<print_csrc>(c)) {
355 std::ios::fmtflags oldflags = c.s.flags();
356 c.s.setf(std::ios::scientific);
357 if (this->is_rational() && !this->is_integer()) {
358 if (compare(_num0) > 0) {
360 if (is_a<print_csrc_cl_N>(c))
361 c.s << "cln::cl_F(\"" << numer().evalf() << "\")";
363 c.s << numer().to_double();
366 if (is_a<print_csrc_cl_N>(c))
367 c.s << "cln::cl_F(\"" << -numer().evalf() << "\")";
369 c.s << -numer().to_double();
372 if (is_a<print_csrc_cl_N>(c))
373 c.s << "cln::cl_F(\"" << denom().evalf() << "\")";
375 c.s << denom().to_double();
378 if (is_a<print_csrc_cl_N>(c))
379 c.s << "cln::cl_F(\"" << evalf() << "\")";
386 const std::string par_open = is_a<print_latex>(c) ? "{(" : "(";
387 const std::string par_close = is_a<print_latex>(c) ? ")}" : ")";
388 const std::string imag_sym = is_a<print_latex>(c) ? "i" : "I";
389 const std::string mul_sym = is_a<print_latex>(c) ? " " : "*";
390 const cln::cl_R r = cln::realpart(cln::the<cln::cl_N>(value));
391 const cln::cl_R i = cln::imagpart(cln::the<cln::cl_N>(value));
393 // case 1, real: x or -x
394 if ((precedence() <= level) && (!this->is_nonneg_integer())) {
396 print_real_number(c, r);
399 print_real_number(c, r);
403 // case 2, imaginary: y*I or -y*I
404 if ((precedence() <= level) && (i < 0)) {
406 c.s << par_open+imag_sym+par_close;
409 print_real_number(c, i);
410 c.s << mul_sym+imag_sym+par_close;
417 c.s << "-" << imag_sym;
419 print_real_number(c, i);
420 c.s << mul_sym+imag_sym;
425 // case 3, complex: x+y*I or x-y*I or -x+y*I or -x-y*I
426 if (precedence() <= level)
428 print_real_number(c, r);
433 print_real_number(c, i);
434 c.s << mul_sym+imag_sym;
441 print_real_number(c, i);
442 c.s << mul_sym+imag_sym;
445 if (precedence() <= level)
452 bool numeric::info(unsigned inf) const
455 case info_flags::numeric:
456 case info_flags::polynomial:
457 case info_flags::rational_function:
459 case info_flags::real:
461 case info_flags::rational:
462 case info_flags::rational_polynomial:
463 return is_rational();
464 case info_flags::crational:
465 case info_flags::crational_polynomial:
466 return is_crational();
467 case info_flags::integer:
468 case info_flags::integer_polynomial:
470 case info_flags::cinteger:
471 case info_flags::cinteger_polynomial:
472 return is_cinteger();
473 case info_flags::positive:
474 return is_positive();
475 case info_flags::negative:
476 return is_negative();
477 case info_flags::nonnegative:
478 return !is_negative();
479 case info_flags::posint:
480 return is_pos_integer();
481 case info_flags::negint:
482 return is_integer() && is_negative();
483 case info_flags::nonnegint:
484 return is_nonneg_integer();
485 case info_flags::even:
487 case info_flags::odd:
489 case info_flags::prime:
491 case info_flags::algebraic:
497 /** Disassemble real part and imaginary part to scan for the occurrence of a
498 * single number. Also handles the imaginary unit. It ignores the sign on
499 * both this and the argument, which may lead to what might appear as funny
500 * results: (2+I).has(-2) -> true. But this is consistent, since we also
501 * would like to have (-2+I).has(2) -> true and we want to think about the
502 * sign as a multiplicative factor. */
503 bool numeric::has(const ex &other) const
505 if (!is_ex_exactly_of_type(other, numeric))
507 const numeric &o = ex_to<numeric>(other);
508 if (this->is_equal(o) || this->is_equal(-o))
510 if (o.imag().is_zero()) // e.g. scan for 3 in -3*I
511 return (this->real().is_equal(o) || this->imag().is_equal(o) ||
512 this->real().is_equal(-o) || this->imag().is_equal(-o));
514 if (o.is_equal(I)) // e.g scan for I in 42*I
515 return !this->is_real();
516 if (o.real().is_zero()) // e.g. scan for 2*I in 2*I+1
517 return (this->real().has(o*I) || this->imag().has(o*I) ||
518 this->real().has(-o*I) || this->imag().has(-o*I));
524 /** Evaluation of numbers doesn't do anything at all. */
525 ex numeric::eval(int level) const
527 // Warning: if this is ever gonna do something, the ex ctors from all kinds
528 // of numbers should be checking for status_flags::evaluated.
533 /** Cast numeric into a floating-point object. For example exact numeric(1) is
534 * returned as a 1.0000000000000000000000 and so on according to how Digits is
535 * currently set. In case the object already was a floating point number the
536 * precision is trimmed to match the currently set default.
538 * @param level ignored, only needed for overriding basic::evalf.
539 * @return an ex-handle to a numeric. */
540 ex numeric::evalf(int level) const
542 // level can safely be discarded for numeric objects.
543 return numeric(cln::cl_float(1.0, cln::default_float_format) *
544 (cln::the<cln::cl_N>(value)));
549 int numeric::compare_same_type(const basic &other) const
551 GINAC_ASSERT(is_exactly_a<numeric>(other));
552 const numeric &o = static_cast<const numeric &>(other);
554 return this->compare(o);
558 bool numeric::is_equal_same_type(const basic &other) const
560 GINAC_ASSERT(is_exactly_a<numeric>(other));
561 const numeric &o = static_cast<const numeric &>(other);
563 return this->is_equal(o);
567 unsigned numeric::calchash(void) const
569 // Use CLN's hashcode. Warning: It depends only on the number's value, not
570 // its type or precision (i.e. a true equivalence relation on numbers). As
571 // a consequence, 3 and 3.0 share the same hashvalue.
572 setflag(status_flags::hash_calculated);
573 return (hashvalue = cln::equal_hashcode(cln::the<cln::cl_N>(value)) | 0x80000000U);
578 // new virtual functions which can be overridden by derived classes
584 // non-virtual functions in this class
589 /** Numerical addition method. Adds argument to *this and returns result as
590 * a numeric object. */
591 const numeric numeric::add(const numeric &other) const
593 // Efficiency shortcut: trap the neutral element by pointer.
596 else if (&other==_num0_p)
599 return numeric(cln::the<cln::cl_N>(value)+cln::the<cln::cl_N>(other.value));
603 /** Numerical subtraction method. Subtracts argument from *this and returns
604 * result as a numeric object. */
605 const numeric numeric::sub(const numeric &other) const
607 return numeric(cln::the<cln::cl_N>(value)-cln::the<cln::cl_N>(other.value));
611 /** Numerical multiplication method. Multiplies *this and argument and returns
612 * result as a numeric object. */
613 const numeric numeric::mul(const numeric &other) const
615 // Efficiency shortcut: trap the neutral element by pointer.
618 else if (&other==_num1_p)
621 return numeric(cln::the<cln::cl_N>(value)*cln::the<cln::cl_N>(other.value));
625 /** Numerical division method. Divides *this by argument and returns result as
628 * @exception overflow_error (division by zero) */
629 const numeric numeric::div(const numeric &other) const
631 if (cln::zerop(cln::the<cln::cl_N>(other.value)))
632 throw std::overflow_error("numeric::div(): division by zero");
633 return numeric(cln::the<cln::cl_N>(value)/cln::the<cln::cl_N>(other.value));
637 /** Numerical exponentiation. Raises *this to the power given as argument and
638 * returns result as a numeric object. */
639 const numeric numeric::power(const numeric &other) const
641 // Efficiency shortcut: trap the neutral exponent by pointer.
645 if (cln::zerop(cln::the<cln::cl_N>(value))) {
646 if (cln::zerop(cln::the<cln::cl_N>(other.value)))
647 throw std::domain_error("numeric::eval(): pow(0,0) is undefined");
648 else if (cln::zerop(cln::realpart(cln::the<cln::cl_N>(other.value))))
649 throw std::domain_error("numeric::eval(): pow(0,I) is undefined");
650 else if (cln::minusp(cln::realpart(cln::the<cln::cl_N>(other.value))))
651 throw std::overflow_error("numeric::eval(): division by zero");
655 return numeric(cln::expt(cln::the<cln::cl_N>(value),cln::the<cln::cl_N>(other.value)));
659 const numeric &numeric::add_dyn(const numeric &other) const
661 // Efficiency shortcut: trap the neutral element by pointer.
664 else if (&other==_num0_p)
667 return static_cast<const numeric &>((new numeric(cln::the<cln::cl_N>(value)+cln::the<cln::cl_N>(other.value)))->
668 setflag(status_flags::dynallocated));
672 const numeric &numeric::sub_dyn(const numeric &other) const
674 return static_cast<const numeric &>((new numeric(cln::the<cln::cl_N>(value)-cln::the<cln::cl_N>(other.value)))->
675 setflag(status_flags::dynallocated));
679 const numeric &numeric::mul_dyn(const numeric &other) const
681 // Efficiency shortcut: trap the neutral element by pointer.
684 else if (&other==_num1_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 const numeric &numeric::div_dyn(const numeric &other) const
694 if (cln::zerop(cln::the<cln::cl_N>(other.value)))
695 throw std::overflow_error("division by zero");
696 return static_cast<const numeric &>((new numeric(cln::the<cln::cl_N>(value)/cln::the<cln::cl_N>(other.value)))->
697 setflag(status_flags::dynallocated));
701 const numeric &numeric::power_dyn(const numeric &other) const
703 // Efficiency shortcut: trap the neutral exponent by pointer.
707 if (cln::zerop(cln::the<cln::cl_N>(value))) {
708 if (cln::zerop(cln::the<cln::cl_N>(other.value)))
709 throw std::domain_error("numeric::eval(): pow(0,0) is undefined");
710 else if (cln::zerop(cln::realpart(cln::the<cln::cl_N>(other.value))))
711 throw std::domain_error("numeric::eval(): pow(0,I) is undefined");
712 else if (cln::minusp(cln::realpart(cln::the<cln::cl_N>(other.value))))
713 throw std::overflow_error("numeric::eval(): division by zero");
717 return static_cast<const numeric &>((new numeric(cln::expt(cln::the<cln::cl_N>(value),cln::the<cln::cl_N>(other.value))))->
718 setflag(status_flags::dynallocated));
722 const numeric &numeric::operator=(int i)
724 return operator=(numeric(i));
728 const numeric &numeric::operator=(unsigned int i)
730 return operator=(numeric(i));
734 const numeric &numeric::operator=(long i)
736 return operator=(numeric(i));
740 const numeric &numeric::operator=(unsigned long i)
742 return operator=(numeric(i));
746 const numeric &numeric::operator=(double d)
748 return operator=(numeric(d));
752 const numeric &numeric::operator=(const char * s)
754 return operator=(numeric(s));
758 /** Inverse of a number. */
759 const numeric numeric::inverse(void) const
761 if (cln::zerop(cln::the<cln::cl_N>(value)))
762 throw std::overflow_error("numeric::inverse(): division by zero");
763 return numeric(cln::recip(cln::the<cln::cl_N>(value)));
767 /** Return the complex half-plane (left or right) in which the number lies.
768 * csgn(x)==0 for x==0, csgn(x)==1 for Re(x)>0 or Re(x)=0 and Im(x)>0,
769 * csgn(x)==-1 for Re(x)<0 or Re(x)=0 and Im(x)<0.
771 * @see numeric::compare(const numeric &other) */
772 int numeric::csgn(void) const
774 if (cln::zerop(cln::the<cln::cl_N>(value)))
776 cln::cl_R r = cln::realpart(cln::the<cln::cl_N>(value));
777 if (!cln::zerop(r)) {
783 if (cln::plusp(cln::imagpart(cln::the<cln::cl_N>(value))))
791 /** This method establishes a canonical order on all numbers. For complex
792 * numbers this is not possible in a mathematically consistent way but we need
793 * to establish some order and it ought to be fast. So we simply define it
794 * to be compatible with our method csgn.
796 * @return csgn(*this-other)
797 * @see numeric::csgn(void) */
798 int numeric::compare(const numeric &other) const
800 // Comparing two real numbers?
801 if (cln::instanceof(value, cln::cl_R_ring) &&
802 cln::instanceof(other.value, cln::cl_R_ring))
803 // Yes, so just cln::compare them
804 return cln::compare(cln::the<cln::cl_R>(value), cln::the<cln::cl_R>(other.value));
806 // No, first cln::compare real parts...
807 cl_signean real_cmp = cln::compare(cln::realpart(cln::the<cln::cl_N>(value)), cln::realpart(cln::the<cln::cl_N>(other.value)));
810 // ...and then the imaginary parts.
811 return cln::compare(cln::imagpart(cln::the<cln::cl_N>(value)), cln::imagpart(cln::the<cln::cl_N>(other.value)));
816 bool numeric::is_equal(const numeric &other) const
818 return cln::equal(cln::the<cln::cl_N>(value),cln::the<cln::cl_N>(other.value));
822 /** True if object is zero. */
823 bool numeric::is_zero(void) const
825 return cln::zerop(cln::the<cln::cl_N>(value));
829 /** True if object is not complex and greater than zero. */
830 bool numeric::is_positive(void) const
833 return cln::plusp(cln::the<cln::cl_R>(value));
838 /** True if object is not complex and less than zero. */
839 bool numeric::is_negative(void) const
842 return cln::minusp(cln::the<cln::cl_R>(value));
847 /** True if object is a non-complex integer. */
848 bool numeric::is_integer(void) const
850 return cln::instanceof(value, cln::cl_I_ring);
854 /** True if object is an exact integer greater than zero. */
855 bool numeric::is_pos_integer(void) const
857 return (this->is_integer() && cln::plusp(cln::the<cln::cl_I>(value)));
861 /** True if object is an exact integer greater or equal zero. */
862 bool numeric::is_nonneg_integer(void) const
864 return (this->is_integer() && !cln::minusp(cln::the<cln::cl_I>(value)));
868 /** True if object is an exact even integer. */
869 bool numeric::is_even(void) const
871 return (this->is_integer() && cln::evenp(cln::the<cln::cl_I>(value)));
875 /** True if object is an exact odd integer. */
876 bool numeric::is_odd(void) const
878 return (this->is_integer() && cln::oddp(cln::the<cln::cl_I>(value)));
882 /** Probabilistic primality test.
884 * @return true if object is exact integer and prime. */
885 bool numeric::is_prime(void) const
887 return (this->is_integer() && cln::isprobprime(cln::the<cln::cl_I>(value)));
891 /** True if object is an exact rational number, may even be complex
892 * (denominator may be unity). */
893 bool numeric::is_rational(void) const
895 return cln::instanceof(value, cln::cl_RA_ring);
899 /** True if object is a real integer, rational or float (but not complex). */
900 bool numeric::is_real(void) const
902 return cln::instanceof(value, cln::cl_R_ring);
906 bool numeric::operator==(const numeric &other) const
908 return cln::equal(cln::the<cln::cl_N>(value), cln::the<cln::cl_N>(other.value));
912 bool numeric::operator!=(const numeric &other) const
914 return !cln::equal(cln::the<cln::cl_N>(value), cln::the<cln::cl_N>(other.value));
918 /** True if object is element of the domain of integers extended by I, i.e. is
919 * of the form a+b*I, where a and b are integers. */
920 bool numeric::is_cinteger(void) const
922 if (cln::instanceof(value, cln::cl_I_ring))
924 else if (!this->is_real()) { // complex case, handle n+m*I
925 if (cln::instanceof(cln::realpart(cln::the<cln::cl_N>(value)), cln::cl_I_ring) &&
926 cln::instanceof(cln::imagpart(cln::the<cln::cl_N>(value)), cln::cl_I_ring))
933 /** True if object is an exact rational number, may even be complex
934 * (denominator may be unity). */
935 bool numeric::is_crational(void) const
937 if (cln::instanceof(value, cln::cl_RA_ring))
939 else if (!this->is_real()) { // complex case, handle Q(i):
940 if (cln::instanceof(cln::realpart(cln::the<cln::cl_N>(value)), cln::cl_RA_ring) &&
941 cln::instanceof(cln::imagpart(cln::the<cln::cl_N>(value)), cln::cl_RA_ring))
948 /** Numerical comparison: less.
950 * @exception invalid_argument (complex inequality) */
951 bool numeric::operator<(const numeric &other) const
953 if (this->is_real() && other.is_real())
954 return (cln::the<cln::cl_R>(value) < cln::the<cln::cl_R>(other.value));
955 throw std::invalid_argument("numeric::operator<(): complex inequality");
959 /** Numerical comparison: less or equal.
961 * @exception invalid_argument (complex inequality) */
962 bool numeric::operator<=(const numeric &other) const
964 if (this->is_real() && other.is_real())
965 return (cln::the<cln::cl_R>(value) <= cln::the<cln::cl_R>(other.value));
966 throw std::invalid_argument("numeric::operator<=(): complex inequality");
970 /** Numerical comparison: greater.
972 * @exception invalid_argument (complex inequality) */
973 bool numeric::operator>(const numeric &other) const
975 if (this->is_real() && other.is_real())
976 return (cln::the<cln::cl_R>(value) > cln::the<cln::cl_R>(other.value));
977 throw std::invalid_argument("numeric::operator>(): complex inequality");
981 /** Numerical comparison: greater or equal.
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 /** Converts numeric types to machine's int. You should check with
993 * is_integer() if the number is really an integer before calling this method.
994 * You may also consider checking the range first. */
995 int numeric::to_int(void) const
997 GINAC_ASSERT(this->is_integer());
998 return cln::cl_I_to_int(cln::the<cln::cl_I>(value));
1002 /** Converts numeric types to machine's long. You should check with
1003 * is_integer() if the number is really an integer before calling this method.
1004 * You may also consider checking the range first. */
1005 long numeric::to_long(void) const
1007 GINAC_ASSERT(this->is_integer());
1008 return cln::cl_I_to_long(cln::the<cln::cl_I>(value));
1012 /** Converts numeric types to machine's double. You should check with is_real()
1013 * if the number is really not complex before calling this method. */
1014 double numeric::to_double(void) const
1016 GINAC_ASSERT(this->is_real());
1017 return cln::double_approx(cln::realpart(cln::the<cln::cl_N>(value)));
1021 /** Returns a new CLN object of type cl_N, representing the value of *this.
1022 * This method may be used when mixing GiNaC and CLN in one project.
1024 cln::cl_N numeric::to_cl_N(void) const
1026 return cln::cl_N(cln::the<cln::cl_N>(value));
1030 /** Real part of a number. */
1031 const numeric numeric::real(void) const
1033 return numeric(cln::realpart(cln::the<cln::cl_N>(value)));
1037 /** Imaginary part of a number. */
1038 const numeric numeric::imag(void) const
1040 return numeric(cln::imagpart(cln::the<cln::cl_N>(value)));
1044 /** Numerator. Computes the numerator of rational numbers, rationalized
1045 * numerator of complex if real and imaginary part are both rational numbers
1046 * (i.e numer(4/3+5/6*I) == 8+5*I), the number carrying the sign in all other
1048 const numeric numeric::numer(void) const
1050 if (this->is_integer())
1051 return numeric(*this);
1053 else if (cln::instanceof(value, cln::cl_RA_ring))
1054 return numeric(cln::numerator(cln::the<cln::cl_RA>(value)));
1056 else if (!this->is_real()) { // complex case, handle Q(i):
1057 const cln::cl_RA r = cln::the<cln::cl_RA>(cln::realpart(cln::the<cln::cl_N>(value)));
1058 const cln::cl_RA i = cln::the<cln::cl_RA>(cln::imagpart(cln::the<cln::cl_N>(value)));
1059 if (cln::instanceof(r, cln::cl_I_ring) && cln::instanceof(i, cln::cl_I_ring))
1060 return numeric(*this);
1061 if (cln::instanceof(r, cln::cl_I_ring) && cln::instanceof(i, cln::cl_RA_ring))
1062 return numeric(cln::complex(r*cln::denominator(i), cln::numerator(i)));
1063 if (cln::instanceof(r, cln::cl_RA_ring) && cln::instanceof(i, cln::cl_I_ring))
1064 return numeric(cln::complex(cln::numerator(r), i*cln::denominator(r)));
1065 if (cln::instanceof(r, cln::cl_RA_ring) && cln::instanceof(i, cln::cl_RA_ring)) {
1066 const cln::cl_I s = cln::lcm(cln::denominator(r), cln::denominator(i));
1067 return numeric(cln::complex(cln::numerator(r)*(cln::exquo(s,cln::denominator(r))),
1068 cln::numerator(i)*(cln::exquo(s,cln::denominator(i)))));
1071 // at least one float encountered
1072 return numeric(*this);
1076 /** Denominator. Computes the denominator of rational numbers, common integer
1077 * denominator of complex if real and imaginary part are both rational numbers
1078 * (i.e denom(4/3+5/6*I) == 6), one in all other cases. */
1079 const numeric numeric::denom(void) const
1081 if (this->is_integer())
1084 if (cln::instanceof(value, cln::cl_RA_ring))
1085 return numeric(cln::denominator(cln::the<cln::cl_RA>(value)));
1087 if (!this->is_real()) { // complex case, handle Q(i):
1088 const cln::cl_RA r = cln::the<cln::cl_RA>(cln::realpart(cln::the<cln::cl_N>(value)));
1089 const cln::cl_RA i = cln::the<cln::cl_RA>(cln::imagpart(cln::the<cln::cl_N>(value)));
1090 if (cln::instanceof(r, cln::cl_I_ring) && cln::instanceof(i, cln::cl_I_ring))
1092 if (cln::instanceof(r, cln::cl_I_ring) && cln::instanceof(i, cln::cl_RA_ring))
1093 return numeric(cln::denominator(i));
1094 if (cln::instanceof(r, cln::cl_RA_ring) && cln::instanceof(i, cln::cl_I_ring))
1095 return numeric(cln::denominator(r));
1096 if (cln::instanceof(r, cln::cl_RA_ring) && cln::instanceof(i, cln::cl_RA_ring))
1097 return numeric(cln::lcm(cln::denominator(r), cln::denominator(i)));
1099 // at least one float encountered
1104 /** Size in binary notation. For integers, this is the smallest n >= 0 such
1105 * that -2^n <= x < 2^n. If x > 0, this is the unique n > 0 such that
1106 * 2^(n-1) <= x < 2^n.
1108 * @return number of bits (excluding sign) needed to represent that number
1109 * in two's complement if it is an integer, 0 otherwise. */
1110 int numeric::int_length(void) const
1112 if (this->is_integer())
1113 return cln::integer_length(cln::the<cln::cl_I>(value));
1122 /** Imaginary unit. This is not a constant but a numeric since we are
1123 * natively handing complex numbers anyways, so in each expression containing
1124 * an I it is automatically eval'ed away anyhow. */
1125 const numeric I = numeric(cln::complex(cln::cl_I(0),cln::cl_I(1)));
1128 /** Exponential function.
1130 * @return arbitrary precision numerical exp(x). */
1131 const numeric exp(const numeric &x)
1133 return cln::exp(x.to_cl_N());
1137 /** Natural logarithm.
1139 * @param z complex number
1140 * @return arbitrary precision numerical log(x).
1141 * @exception pole_error("log(): logarithmic pole",0) */
1142 const numeric log(const numeric &z)
1145 throw pole_error("log(): logarithmic pole",0);
1146 return cln::log(z.to_cl_N());
1150 /** Numeric sine (trigonometric function).
1152 * @return arbitrary precision numerical sin(x). */
1153 const numeric sin(const numeric &x)
1155 return cln::sin(x.to_cl_N());
1159 /** Numeric cosine (trigonometric function).
1161 * @return arbitrary precision numerical cos(x). */
1162 const numeric cos(const numeric &x)
1164 return cln::cos(x.to_cl_N());
1168 /** Numeric tangent (trigonometric function).
1170 * @return arbitrary precision numerical tan(x). */
1171 const numeric tan(const numeric &x)
1173 return cln::tan(x.to_cl_N());
1177 /** Numeric inverse sine (trigonometric function).
1179 * @return arbitrary precision numerical asin(x). */
1180 const numeric asin(const numeric &x)
1182 return cln::asin(x.to_cl_N());
1186 /** Numeric inverse cosine (trigonometric function).
1188 * @return arbitrary precision numerical acos(x). */
1189 const numeric acos(const numeric &x)
1191 return cln::acos(x.to_cl_N());
1197 * @param z complex number
1199 * @exception pole_error("atan(): logarithmic pole",0) */
1200 const numeric atan(const numeric &x)
1203 x.real().is_zero() &&
1204 abs(x.imag()).is_equal(_num1))
1205 throw pole_error("atan(): logarithmic pole",0);
1206 return cln::atan(x.to_cl_N());
1212 * @param x real number
1213 * @param y real number
1214 * @return atan(y/x) */
1215 const numeric atan(const numeric &y, const numeric &x)
1217 if (x.is_real() && y.is_real())
1218 return cln::atan(cln::the<cln::cl_R>(x.to_cl_N()),
1219 cln::the<cln::cl_R>(y.to_cl_N()));
1221 throw std::invalid_argument("atan(): complex argument");
1225 /** Numeric hyperbolic sine (trigonometric function).
1227 * @return arbitrary precision numerical sinh(x). */
1228 const numeric sinh(const numeric &x)
1230 return cln::sinh(x.to_cl_N());
1234 /** Numeric hyperbolic cosine (trigonometric function).
1236 * @return arbitrary precision numerical cosh(x). */
1237 const numeric cosh(const numeric &x)
1239 return cln::cosh(x.to_cl_N());
1243 /** Numeric hyperbolic tangent (trigonometric function).
1245 * @return arbitrary precision numerical tanh(x). */
1246 const numeric tanh(const numeric &x)
1248 return cln::tanh(x.to_cl_N());
1252 /** Numeric inverse hyperbolic sine (trigonometric function).
1254 * @return arbitrary precision numerical asinh(x). */
1255 const numeric asinh(const numeric &x)
1257 return cln::asinh(x.to_cl_N());
1261 /** Numeric inverse hyperbolic cosine (trigonometric function).
1263 * @return arbitrary precision numerical acosh(x). */
1264 const numeric acosh(const numeric &x)
1266 return cln::acosh(x.to_cl_N());
1270 /** Numeric inverse hyperbolic tangent (trigonometric function).
1272 * @return arbitrary precision numerical atanh(x). */
1273 const numeric atanh(const numeric &x)
1275 return cln::atanh(x.to_cl_N());
1279 /*static cln::cl_N Li2_series(const ::cl_N &x,
1280 const ::float_format_t &prec)
1282 // Note: argument must be in the unit circle
1283 // This is very inefficient unless we have fast floating point Bernoulli
1284 // numbers implemented!
1285 cln::cl_N c1 = -cln::log(1-x);
1287 // hard-wire the first two Bernoulli numbers
1288 cln::cl_N acc = c1 - cln::square(c1)/4;
1290 cln::cl_F pisq = cln::square(cln::cl_pi(prec)); // pi^2
1291 cln::cl_F piac = cln::cl_float(1, prec); // accumulator: pi^(2*i)
1293 c1 = cln::square(c1);
1297 aug = c2 * (*(bernoulli(numeric(2*i)).clnptr())) / cln::factorial(2*i+1);
1298 // 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));
1301 } while (acc != acc+aug);
1305 /** Numeric evaluation of Dilogarithm within circle of convergence (unit
1306 * circle) using a power series. */
1307 static cln::cl_N Li2_series(const cln::cl_N &x,
1308 const cln::float_format_t &prec)
1310 // Note: argument must be in the unit circle
1312 cln::cl_N num = cln::complex(cln::cl_float(1, prec), 0);
1317 den = den + i; // 1, 4, 9, 16, ...
1321 } while (acc != acc+aug);
1325 /** Folds Li2's argument inside a small rectangle to enhance convergence. */
1326 static cln::cl_N Li2_projection(const cln::cl_N &x,
1327 const cln::float_format_t &prec)
1329 const cln::cl_R re = cln::realpart(x);
1330 const cln::cl_R im = cln::imagpart(x);
1331 if (re > cln::cl_F(".5"))
1332 // zeta(2) - Li2(1-x) - log(x)*log(1-x)
1334 - Li2_series(1-x, prec)
1335 - cln::log(x)*cln::log(1-x));
1336 if ((re <= 0 && cln::abs(im) > cln::cl_F(".75")) || (re < cln::cl_F("-.5")))
1337 // -log(1-x)^2 / 2 - Li2(x/(x-1))
1338 return(- cln::square(cln::log(1-x))/2
1339 - Li2_series(x/(x-1), prec));
1340 if (re > 0 && cln::abs(im) > cln::cl_LF(".75"))
1341 // Li2(x^2)/2 - Li2(-x)
1342 return(Li2_projection(cln::square(x), prec)/2
1343 - Li2_projection(-x, prec));
1344 return Li2_series(x, prec);
1347 /** Numeric evaluation of Dilogarithm. The domain is the entire complex plane,
1348 * the branch cut lies along the positive real axis, starting at 1 and
1349 * continuous with quadrant IV.
1351 * @return arbitrary precision numerical Li2(x). */
1352 const numeric Li2(const numeric &x)
1357 // what is the desired float format?
1358 // first guess: default format
1359 cln::float_format_t prec = cln::default_float_format;
1360 const cln::cl_N value = x.to_cl_N();
1361 // second guess: the argument's format
1362 if (!x.real().is_rational())
1363 prec = cln::float_format(cln::the<cln::cl_F>(cln::realpart(value)));
1364 else if (!x.imag().is_rational())
1365 prec = cln::float_format(cln::the<cln::cl_F>(cln::imagpart(value)));
1367 if (cln::the<cln::cl_N>(value)==1) // may cause trouble with log(1-x)
1368 return cln::zeta(2, prec);
1370 if (cln::abs(value) > 1)
1371 // -log(-x)^2 / 2 - zeta(2) - Li2(1/x)
1372 return(- cln::square(cln::log(-value))/2
1373 - cln::zeta(2, prec)
1374 - Li2_projection(cln::recip(value), prec));
1376 return Li2_projection(x.to_cl_N(), prec);
1380 /** Numeric evaluation of Riemann's Zeta function. Currently works only for
1381 * integer arguments. */
1382 const numeric zeta(const numeric &x)
1384 // A dirty hack to allow for things like zeta(3.0), since CLN currently
1385 // only knows about integer arguments and zeta(3).evalf() automatically
1386 // cascades down to zeta(3.0).evalf(). The trick is to rely on 3.0-3
1387 // being an exact zero for CLN, which can be tested and then we can just
1388 // pass the number casted to an int:
1390 const int aux = (int)(cln::double_approx(cln::the<cln::cl_R>(x.to_cl_N())));
1391 if (cln::zerop(x.to_cl_N()-aux))
1392 return cln::zeta(aux);
1398 /** The Gamma function.
1399 * This is only a stub! */
1400 const numeric lgamma(const numeric &x)
1404 const numeric tgamma(const numeric &x)
1410 /** The psi function (aka polygamma function).
1411 * This is only a stub! */
1412 const numeric psi(const numeric &x)
1418 /** The psi functions (aka polygamma functions).
1419 * This is only a stub! */
1420 const numeric psi(const numeric &n, const numeric &x)
1426 /** Factorial combinatorial function.
1428 * @param n integer argument >= 0
1429 * @exception range_error (argument must be integer >= 0) */
1430 const numeric factorial(const numeric &n)
1432 if (!n.is_nonneg_integer())
1433 throw std::range_error("numeric::factorial(): argument must be integer >= 0");
1434 return numeric(cln::factorial(n.to_int()));
1438 /** The double factorial combinatorial function. (Scarcely used, but still
1439 * useful in cases, like for exact results of tgamma(n+1/2) for instance.)
1441 * @param n integer argument >= -1
1442 * @return n!! == n * (n-2) * (n-4) * ... * ({1|2}) with 0!! == (-1)!! == 1
1443 * @exception range_error (argument must be integer >= -1) */
1444 const numeric doublefactorial(const numeric &n)
1446 if (n.is_equal(_num_1))
1449 if (!n.is_nonneg_integer())
1450 throw std::range_error("numeric::doublefactorial(): argument must be integer >= -1");
1452 return numeric(cln::doublefactorial(n.to_int()));
1456 /** The Binomial coefficients. It computes the binomial coefficients. For
1457 * integer n and k and positive n this is the number of ways of choosing k
1458 * objects from n distinct objects. If n is negative, the formula
1459 * binomial(n,k) == (-1)^k*binomial(k-n-1,k) is used to compute the result. */
1460 const numeric binomial(const numeric &n, const numeric &k)
1462 if (n.is_integer() && k.is_integer()) {
1463 if (n.is_nonneg_integer()) {
1464 if (k.compare(n)!=1 && k.compare(_num0)!=-1)
1465 return numeric(cln::binomial(n.to_int(),k.to_int()));
1469 return _num_1.power(k)*binomial(k-n-_num1,k);
1473 // should really be gamma(n+1)/gamma(r+1)/gamma(n-r+1) or a suitable limit
1474 throw std::range_error("numeric::binomial(): don´t know how to evaluate that.");
1478 /** Bernoulli number. The nth Bernoulli number is the coefficient of x^n/n!
1479 * in the expansion of the function x/(e^x-1).
1481 * @return the nth Bernoulli number (a rational number).
1482 * @exception range_error (argument must be integer >= 0) */
1483 const numeric bernoulli(const numeric &nn)
1485 if (!nn.is_integer() || nn.is_negative())
1486 throw std::range_error("numeric::bernoulli(): argument must be integer >= 0");
1490 // The Bernoulli numbers are rational numbers that may be computed using
1493 // B_n = - 1/(n+1) * sum_{k=0}^{n-1}(binomial(n+1,k)*B_k)
1495 // with B(0) = 1. Since the n'th Bernoulli number depends on all the
1496 // previous ones, the computation is necessarily very expensive. There are
1497 // several other ways of computing them, a particularly good one being
1501 // for (unsigned i=0; i<n; i++) {
1502 // c = exquo(c*(i-n),(i+2));
1503 // Bern = Bern + c*s/(i+2);
1504 // s = s + expt_pos(cl_I(i+2),n);
1508 // But if somebody works with the n'th Bernoulli number she is likely to
1509 // also need all previous Bernoulli numbers. So we need a complete remember
1510 // table and above divide and conquer algorithm is not suited to build one
1511 // up. The code below is adapted from Pari's function bernvec().
1513 // (There is an interesting relation with the tangent polynomials described
1514 // in `Concrete Mathematics', which leads to a program twice as fast as our
1515 // implementation below, but it requires storing one such polynomial in
1516 // addition to the remember table. This doubles the memory footprint so
1517 // we don't use it.)
1519 // the special cases not covered by the algorithm below
1520 if (nn.is_equal(_num1))
1525 // store nonvanishing Bernoulli numbers here
1526 static std::vector< cln::cl_RA > results;
1527 static int highest_result = 0;
1528 // algorithm not applicable to B(0), so just store it
1529 if (results.empty())
1530 results.push_back(cln::cl_RA(1));
1532 int n = nn.to_long();
1533 for (int i=highest_result; i<n/2; ++i) {
1539 for (int j=i; j>0; --j) {
1540 B = cln::cl_I(n*m) * (B+results[j]) / (d1*d2);
1546 B = (1 - ((B+1)/(2*i+3))) / (cln::cl_I(1)<<(2*i+2));
1547 results.push_back(B);
1550 return results[n/2];
1554 /** Fibonacci number. The nth Fibonacci number F(n) is defined by the
1555 * recurrence formula F(n)==F(n-1)+F(n-2) with F(0)==0 and F(1)==1.
1557 * @param n an integer
1558 * @return the nth Fibonacci number F(n) (an integer number)
1559 * @exception range_error (argument must be an integer) */
1560 const numeric fibonacci(const numeric &n)
1562 if (!n.is_integer())
1563 throw std::range_error("numeric::fibonacci(): argument must be integer");
1566 // The following addition formula holds:
1568 // F(n+m) = F(m-1)*F(n) + F(m)*F(n+1) for m >= 1, n >= 0.
1570 // (Proof: For fixed m, the LHS and the RHS satisfy the same recurrence
1571 // w.r.t. n, and the initial values (n=0, n=1) agree. Hence all values
1573 // Replace m by m+1:
1574 // F(n+m+1) = F(m)*F(n) + F(m+1)*F(n+1) for m >= 0, n >= 0
1575 // Now put in m = n, to get
1576 // F(2n) = (F(n+1)-F(n))*F(n) + F(n)*F(n+1) = F(n)*(2*F(n+1) - F(n))
1577 // F(2n+1) = F(n)^2 + F(n+1)^2
1579 // F(2n+2) = F(n+1)*(2*F(n) + F(n+1))
1582 if (n.is_negative())
1584 return -fibonacci(-n);
1586 return fibonacci(-n);
1590 cln::cl_I m = cln::the<cln::cl_I>(n.to_cl_N()) >> 1L; // floor(n/2);
1591 for (uintL bit=cln::integer_length(m); bit>0; --bit) {
1592 // Since a squaring is cheaper than a multiplication, better use
1593 // three squarings instead of one multiplication and two squarings.
1594 cln::cl_I u2 = cln::square(u);
1595 cln::cl_I v2 = cln::square(v);
1596 if (cln::logbitp(bit-1, m)) {
1597 v = cln::square(u + v) - u2;
1600 u = v2 - cln::square(v - u);
1605 // Here we don't use the squaring formula because one multiplication
1606 // is cheaper than two squarings.
1607 return u * ((v << 1) - u);
1609 return cln::square(u) + cln::square(v);
1613 /** Absolute value. */
1614 const numeric abs(const numeric& x)
1616 return cln::abs(x.to_cl_N());
1620 /** Modulus (in positive representation).
1621 * In general, mod(a,b) has the sign of b or is zero, and rem(a,b) has the
1622 * sign of a or is zero. This is different from Maple's modp, where the sign
1623 * of b is ignored. It is in agreement with Mathematica's Mod.
1625 * @return a mod b in the range [0,abs(b)-1] with sign of b if both are
1626 * integer, 0 otherwise. */
1627 const numeric mod(const numeric &a, const numeric &b)
1629 if (a.is_integer() && b.is_integer())
1630 return cln::mod(cln::the<cln::cl_I>(a.to_cl_N()),
1631 cln::the<cln::cl_I>(b.to_cl_N()));
1637 /** Modulus (in symmetric representation).
1638 * Equivalent to Maple's mods.
1640 * @return a mod b in the range [-iquo(abs(m)-1,2), iquo(abs(m),2)]. */
1641 const numeric smod(const numeric &a, const numeric &b)
1643 if (a.is_integer() && b.is_integer()) {
1644 const cln::cl_I b2 = cln::ceiling1(cln::the<cln::cl_I>(b.to_cl_N()) >> 1) - 1;
1645 return cln::mod(cln::the<cln::cl_I>(a.to_cl_N()) + b2,
1646 cln::the<cln::cl_I>(b.to_cl_N())) - b2;
1652 /** Numeric integer remainder.
1653 * Equivalent to Maple's irem(a,b) as far as sign conventions are concerned.
1654 * In general, mod(a,b) has the sign of b or is zero, and irem(a,b) has the
1655 * sign of a or is zero.
1657 * @return remainder of a/b if both are integer, 0 otherwise. */
1658 const numeric irem(const numeric &a, const numeric &b)
1660 if (a.is_integer() && b.is_integer())
1661 return cln::rem(cln::the<cln::cl_I>(a.to_cl_N()),
1662 cln::the<cln::cl_I>(b.to_cl_N()));
1668 /** Numeric integer remainder.
1669 * Equivalent to Maple's irem(a,b,'q') it obeyes the relation
1670 * irem(a,b,q) == a - q*b. In general, mod(a,b) has the sign of b or is zero,
1671 * and irem(a,b) has the sign of a or is zero.
1673 * @return remainder of a/b and quotient stored in q if both are integer,
1675 const numeric irem(const numeric &a, const numeric &b, numeric &q)
1677 if (a.is_integer() && b.is_integer()) {
1678 const cln::cl_I_div_t rem_quo = cln::truncate2(cln::the<cln::cl_I>(a.to_cl_N()),
1679 cln::the<cln::cl_I>(b.to_cl_N()));
1680 q = rem_quo.quotient;
1681 return rem_quo.remainder;
1689 /** Numeric integer quotient.
1690 * Equivalent to Maple's iquo as far as sign conventions are concerned.
1692 * @return truncated quotient of a/b if both are integer, 0 otherwise. */
1693 const numeric iquo(const numeric &a, const numeric &b)
1695 if (a.is_integer() && b.is_integer())
1696 return cln::truncate1(cln::the<cln::cl_I>(a.to_cl_N()),
1697 cln::the<cln::cl_I>(b.to_cl_N()));
1703 /** Numeric integer quotient.
1704 * Equivalent to Maple's iquo(a,b,'r') it obeyes the relation
1705 * r == a - iquo(a,b,r)*b.
1707 * @return truncated quotient of a/b and remainder stored in r if both are
1708 * integer, 0 otherwise. */
1709 const numeric iquo(const numeric &a, const numeric &b, numeric &r)
1711 if (a.is_integer() && b.is_integer()) {
1712 const cln::cl_I_div_t rem_quo = cln::truncate2(cln::the<cln::cl_I>(a.to_cl_N()),
1713 cln::the<cln::cl_I>(b.to_cl_N()));
1714 r = rem_quo.remainder;
1715 return rem_quo.quotient;
1723 /** Greatest Common Divisor.
1725 * @return The GCD of two numbers if both are integer, a numerical 1
1726 * if they are not. */
1727 const numeric gcd(const numeric &a, const numeric &b)
1729 if (a.is_integer() && b.is_integer())
1730 return cln::gcd(cln::the<cln::cl_I>(a.to_cl_N()),
1731 cln::the<cln::cl_I>(b.to_cl_N()));
1737 /** Least Common Multiple.
1739 * @return The LCM of two numbers if both are integer, the product of those
1740 * two numbers if they are not. */
1741 const numeric lcm(const numeric &a, const numeric &b)
1743 if (a.is_integer() && b.is_integer())
1744 return cln::lcm(cln::the<cln::cl_I>(a.to_cl_N()),
1745 cln::the<cln::cl_I>(b.to_cl_N()));
1751 /** Numeric square root.
1752 * If possible, sqrt(z) should respect squares of exact numbers, i.e. sqrt(4)
1753 * should return integer 2.
1755 * @param z numeric argument
1756 * @return square root of z. Branch cut along negative real axis, the negative
1757 * real axis itself where imag(z)==0 and real(z)<0 belongs to the upper part
1758 * where imag(z)>0. */
1759 const numeric sqrt(const numeric &z)
1761 return cln::sqrt(z.to_cl_N());
1765 /** Integer numeric square root. */
1766 const numeric isqrt(const numeric &x)
1768 if (x.is_integer()) {
1770 cln::isqrt(cln::the<cln::cl_I>(x.to_cl_N()), &root);
1777 /** Floating point evaluation of Archimedes' constant Pi. */
1780 return numeric(cln::pi(cln::default_float_format));
1784 /** Floating point evaluation of Euler's constant gamma. */
1787 return numeric(cln::eulerconst(cln::default_float_format));
1791 /** Floating point evaluation of Catalan's constant. */
1792 ex CatalanEvalf(void)
1794 return numeric(cln::catalanconst(cln::default_float_format));
1798 /** _numeric_digits default ctor, checking for singleton invariance. */
1799 _numeric_digits::_numeric_digits()
1802 // It initializes to 17 digits, because in CLN float_format(17) turns out
1803 // to be 61 (<64) while float_format(18)=65. The reason is we want to
1804 // have a cl_LF instead of cl_SF, cl_FF or cl_DF.
1806 throw(std::runtime_error("I told you not to do instantiate me!"));
1808 cln::default_float_format = cln::float_format(17);
1812 /** Assign a native long to global Digits object. */
1813 _numeric_digits& _numeric_digits::operator=(long prec)
1816 cln::default_float_format = cln::float_format(prec);
1821 /** Convert global Digits object to native type long. */
1822 _numeric_digits::operator long()
1824 // BTW, this is approx. unsigned(cln::default_float_format*0.301)-1
1825 return (long)digits;
1829 /** Append global Digits object to ostream. */
1830 void _numeric_digits::print(std::ostream &os) const
1836 std::ostream& operator<<(std::ostream &os, const _numeric_digits &e)
1843 // static member variables
1848 bool _numeric_digits::too_late = false;
1851 /** Accuracy in decimal digits. Only object of this type! Can be set using
1852 * assignment from C++ unsigned ints and evaluated like any built-in type. */
1853 _numeric_digits Digits;
1855 } // namespace GiNaC