numeric::numeric() : basic(TINFO_numeric)
{
debugmsg("numeric default constructor", LOGLEVEL_CONSTRUCT);
- value = new cl_N;
- *value = cl_I(0);
+ value = new ::cl_N;
+ *value = ::cl_I(0);
calchash();
setflag(status_flags::evaluated |
status_flags::expanded |
void numeric::copy(const numeric & other)
{
basic::copy(other);
- value = new cl_N(*other.value);
+ value = new ::cl_N(*other.value);
}
void numeric::destroy(bool call_parent)
// Not the whole int-range is available if we don't cast to long
// first. This is due to the behaviour of the cl_I-ctor, which
// emphasizes efficiency:
- value = new cl_I((long) i);
+ value = new ::cl_I((long) i);
calchash();
setflag(status_flags::evaluated|
status_flags::hash_calculated);
// Not the whole uint-range is available if we don't cast to ulong
// first. This is due to the behaviour of the cl_I-ctor, which
// emphasizes efficiency:
- value = new cl_I((unsigned long)i);
+ value = new ::cl_I((unsigned long)i);
calchash();
setflag(status_flags::evaluated|
status_flags::hash_calculated);
numeric::numeric(long i) : basic(TINFO_numeric)
{
debugmsg("numeric constructor from long",LOGLEVEL_CONSTRUCT);
- value = new cl_I(i);
+ value = new ::cl_I(i);
calchash();
setflag(status_flags::evaluated|
status_flags::hash_calculated);
numeric::numeric(unsigned long i) : basic(TINFO_numeric)
{
debugmsg("numeric constructor from ulong",LOGLEVEL_CONSTRUCT);
- value = new cl_I(i);
+ value = new ::cl_I(i);
calchash();
setflag(status_flags::evaluated|
status_flags::hash_calculated);
debugmsg("numeric constructor from long/long",LOGLEVEL_CONSTRUCT);
if (!denom)
throw (std::overflow_error("division by zero"));
- value = new cl_I(numer);
- *value = *value / cl_I(denom);
+ value = new ::cl_I(numer);
+ *value = *value / ::cl_I(denom);
calchash();
setflag(status_flags::evaluated|
status_flags::hash_calculated);
}
+/** ctor from C-style string. It also accepts complex numbers in GiNaC
+ * notation like "2+5*I". */
numeric::numeric(const char *s) : basic(TINFO_numeric)
-{ // MISSING: treatment of complex and ints and rationals.
+{
debugmsg("numeric constructor from string",LOGLEVEL_CONSTRUCT);
- if (strchr(s, '.'))
- value = new cl_LF(s);
- else
- value = new cl_I(s);
+ value = new ::cl_N(0);
+ // parse complex numbers (functional but not completely safe, unfortunately
+ // std::string does not understand regexpese):
+ // ss should represent a simple sum like 2+5*I
+ std::string ss(s);
+ // make it safe by adding explicit sign
+ if (ss.at(0) != '+' && ss.at(0) != '-' && ss.at(0) != '#')
+ ss = '+' + ss;
+ std::string::size_type delim;
+ do {
+ // chop ss into terms from left to right
+ std::string term;
+ bool imaginary = false;
+ delim = ss.find_first_of(std::string("+-"),1);
+ // Do we have an exponent marker like "31.415E-1"? If so, hop on!
+ if (delim != std::string::npos &&
+ ss.at(delim-1) == 'E')
+ delim = ss.find_first_of(std::string("+-"),delim+1);
+ term = ss.substr(0,delim);
+ if (delim != std::string::npos)
+ ss = ss.substr(delim);
+ // is the term imaginary?
+ if (term.find("I") != std::string::npos) {
+ // erase 'I':
+ term = term.replace(term.find("I"),1,"");
+ // erase '*':
+ if (term.find("*") != std::string::npos)
+ term = term.replace(term.find("*"),1,"");
+ // correct for trivial +/-I without explicit factor on I:
+ if (term.size() == 1)
+ term += "1";
+ imaginary = true;
+ }
+ const char *cs = term.c_str();
+ // CLN's short types are not useful within the GiNaC framework, hence
+ // we go straight to the construction of a long float. Simply using
+ // cl_N(s) would require us to use add a CLN exponent mark, otherwise
+ // we would not be save from over-/underflows.
+ if (strchr(cs, '.'))
+ if (imaginary)
+ *value = *value + ::complex(cl_I(0),::cl_LF(cs));
+ else
+ *value = *value + ::cl_LF(cs);
+ else
+ if (imaginary)
+ *value = *value + ::complex(cl_I(0),::cl_R(cs));
+ else
+ *value = *value + ::cl_R(cs);
+ } while(delim != std::string::npos);
calchash();
setflag(status_flags::evaluated|
status_flags::hash_calculated);
numeric::numeric(const cl_N & z) : basic(TINFO_numeric)
{
debugmsg("numeric constructor from cl_N", LOGLEVEL_CONSTRUCT);
- value = new cl_N(z);
+ value = new ::cl_N(z);
calchash();
setflag(status_flags::evaluated|
status_flags::hash_calculated);
numeric::numeric(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst)
{
debugmsg("numeric constructor from archive_node", LOGLEVEL_CONSTRUCT);
- value = new cl_N;
-#ifdef HAVE_SSTREAM
+ value = new ::cl_N;
+
// Read number as string
- string str;
+ std::string str;
if (n.find_string("number", str)) {
- istringstream s(str);
- cl_idecoded_float re, im;
+#ifdef HAVE_SSTREAM
+ std::istringstream s(str);
+#else
+ std::istrstream s(str.c_str(), str.size() + 1);
+#endif
+ ::cl_idecoded_float re, im;
char c;
s.get(c);
switch (c) {
- case 'N': // Ordinary number
case 'R': // Integer-decoded real number
s >> re.sign >> re.mantissa >> re.exponent;
*value = re.sign * re.mantissa * ::expt(cl_float(2.0, cl_default_float_format), re.exponent);
*value = ::complex(re.sign * re.mantissa * ::expt(cl_float(2.0, cl_default_float_format), re.exponent),
im.sign * im.mantissa * ::expt(cl_float(2.0, cl_default_float_format), im.exponent));
break;
- default: // Ordinary number
- s.putback(c);
+ default: // Ordinary number
+ s.putback(c);
s >> *value;
break;
}
}
-#else
- // Read number as string
- string str;
- if (n.find_string("number", str)) {
- istrstream f(str.c_str(), str.size() + 1);
- cl_idecoded_float re, im;
- char c;
- f.get(c);
- switch (c) {
- case 'R': // Integer-decoded real number
- f >> re.sign >> re.mantissa >> re.exponent;
- *value = re.sign * re.mantissa * ::expt(cl_float(2.0, cl_default_float_format), re.exponent);
- break;
- case 'C': // Integer-decoded complex number
- f >> re.sign >> re.mantissa >> re.exponent;
- f >> im.sign >> im.mantissa >> im.exponent;
- *value = ::complex(re.sign * re.mantissa * ::expt(cl_float(2.0, cl_default_float_format), re.exponent),
- im.sign * im.mantissa * ::expt(cl_float(2.0, cl_default_float_format), im.exponent));
- break;
- default: // Ordinary number
- f.putback(c);
- f >> *value;
- break;
- }
- }
-#endif
calchash();
setflag(status_flags::evaluated|
status_flags::hash_calculated);
void numeric::archive(archive_node &n) const
{
inherited::archive(n);
-#ifdef HAVE_SSTREAM
+
// Write number as string
- ostringstream s;
+#ifdef HAVE_SSTREAM
+ std::ostringstream s;
+#else
+ char buf[1024];
+ std::ostrstream s(buf, 1024);
+#endif
if (this->is_crational())
s << *value;
else {
// Non-rational numbers are written in an integer-decoded format
// to preserve the precision
if (this->is_real()) {
- cl_idecoded_float re = integer_decode_float(The(cl_F)(*value));
+ cl_idecoded_float re = integer_decode_float(The(::cl_F)(*value));
s << "R";
s << re.sign << " " << re.mantissa << " " << re.exponent;
} else {
- cl_idecoded_float re = integer_decode_float(The(cl_F)(::realpart(*value)));
- cl_idecoded_float im = integer_decode_float(The(cl_F)(::imagpart(*value)));
+ cl_idecoded_float re = integer_decode_float(The(::cl_F)(::realpart(*value)));
+ cl_idecoded_float im = integer_decode_float(The(::cl_F)(::imagpart(*value)));
s << "C";
s << re.sign << " " << re.mantissa << " " << re.exponent << " ";
s << im.sign << " " << im.mantissa << " " << im.exponent;
}
}
+#ifdef HAVE_SSTREAM
n.add_string("number", s.str());
#else
- // Write number as string
- char buf[1024];
- ostrstream f(buf, 1024);
- if (this->is_crational())
- f << *value << ends;
- else {
- // Non-rational numbers are written in an integer-decoded format
- // to preserve the precision
- if (this->is_real()) {
- cl_idecoded_float re = integer_decode_float(The(cl_F)(*value));
- f << "R";
- f << re.sign << " " << re.mantissa << " " << re.exponent << ends;
- } else {
- cl_idecoded_float re = integer_decode_float(The(cl_F)(::realpart(*value)));
- cl_idecoded_float im = integer_decode_float(The(cl_F)(::imagpart(*value)));
- f << "C";
- f << re.sign << " " << re.mantissa << " " << re.exponent << " ";
- f << im.sign << " " << im.mantissa << " " << im.exponent << ends;
- }
- }
- string str(buf);
+ s << ends;
+ std::string str(buf);
n.add_string("number", str);
#endif
}
* long as it only uses cl_LF and no other floating point types.
*
* @see numeric::print() */
-void print_real_number(ostream & os, const cl_R & num)
+static void print_real_number(ostream & os, const cl_R & num)
{
cl_print_flags ourflags;
if (::instanceof(num, ::cl_RA_ring)) {
// case 2: float
// make CLN believe this number has default_float_format, so it prints
// 'E' as exponent marker instead of 'L':
- ourflags.default_float_format = ::cl_float_format(The(cl_F)(num));
+ ourflags.default_float_format = ::cl_float_format(The(::cl_F)(num));
::print_real(os, ourflags, num);
}
return;
// case 1, real: x or -x
if ((precedence<=upper_precedence) && (!this->is_nonneg_integer())) {
os << "(";
- print_real_number(os, The(cl_R)(*value));
+ print_real_number(os, The(::cl_R)(*value));
os << ")";
} else {
- print_real_number(os, The(cl_R)(*value));
+ print_real_number(os, The(::cl_R)(*value));
}
} else {
// case 2, imaginary: y*I or -y*I
os << "(-I)";
} else {
os << "(";
- print_real_number(os, The(cl_R)(::imagpart(*value)));
+ print_real_number(os, The(::cl_R)(::imagpart(*value)));
os << "*I)";
}
} else {
if (::imagpart (*value) == -1) {
os << "-I";
} else {
- print_real_number(os, The(cl_R)(::imagpart(*value)));
+ print_real_number(os, The(::cl_R)(::imagpart(*value)));
os << "*I";
}
}
// case 3, complex: x+y*I or x-y*I or -x+y*I or -x-y*I
if (precedence <= upper_precedence)
os << "(";
- print_real_number(os, The(cl_R)(::realpart(*value)));
+ print_real_number(os, The(::cl_R)(::realpart(*value)));
if (::imagpart(*value) < 0) {
if (::imagpart(*value) == -1) {
os << "-I";
} else {
- print_real_number(os, The(cl_R)(::imagpart(*value)));
+ print_real_number(os, The(::cl_R)(::imagpart(*value)));
os << "*I";
}
} else {
os << "+I";
} else {
os << "+";
- print_real_number(os, The(cl_R)(::imagpart(*value)));
+ print_real_number(os, The(::cl_R)(::imagpart(*value)));
os << "*I";
}
}
void numeric::printtree(ostream & os, unsigned indent) const
{
debugmsg("numeric printtree", LOGLEVEL_PRINT);
- os << string(indent,' ') << *value
+ os << std::string(indent,' ') << *value
<< " (numeric): "
<< "hash=" << hashvalue << " (0x" << hex << hashvalue << dec << ")"
<< ", flags=" << flags << endl;
bool numeric::info(unsigned inf) const
{
switch (inf) {
- case info_flags::numeric:
- case info_flags::polynomial:
- case info_flags::rational_function:
- return true;
- case info_flags::real:
- return is_real();
- case info_flags::rational:
- case info_flags::rational_polynomial:
- return is_rational();
- case info_flags::crational:
- case info_flags::crational_polynomial:
- return is_crational();
- case info_flags::integer:
- case info_flags::integer_polynomial:
- return is_integer();
- case info_flags::cinteger:
- case info_flags::cinteger_polynomial:
- return is_cinteger();
- case info_flags::positive:
- return is_positive();
- case info_flags::negative:
- return is_negative();
- case info_flags::nonnegative:
- return !is_negative();
- case info_flags::posint:
- return is_pos_integer();
- case info_flags::negint:
- return is_integer() && is_negative();
- case info_flags::nonnegint:
- return is_nonneg_integer();
- case info_flags::even:
- return is_even();
- case info_flags::odd:
- return is_odd();
- case info_flags::prime:
- return is_prime();
+ case info_flags::numeric:
+ case info_flags::polynomial:
+ case info_flags::rational_function:
+ return true;
+ case info_flags::real:
+ return is_real();
+ case info_flags::rational:
+ case info_flags::rational_polynomial:
+ return is_rational();
+ case info_flags::crational:
+ case info_flags::crational_polynomial:
+ return is_crational();
+ case info_flags::integer:
+ case info_flags::integer_polynomial:
+ return is_integer();
+ case info_flags::cinteger:
+ case info_flags::cinteger_polynomial:
+ return is_cinteger();
+ case info_flags::positive:
+ return is_positive();
+ case info_flags::negative:
+ return is_negative();
+ case info_flags::nonnegative:
+ return !is_negative();
+ case info_flags::posint:
+ return is_pos_integer();
+ case info_flags::negint:
+ return is_integer() && is_negative();
+ case info_flags::nonnegint:
+ return is_nonneg_integer();
+ case info_flags::even:
+ return is_even();
+ case info_flags::odd:
+ return is_odd();
+ case info_flags::prime:
+ return is_prime();
+ case info_flags::algebraic:
+ return !is_real();
}
return false;
}
return this->is_equal(*o);
}
-unsigned numeric::calchash(void) const
-{
- return (hashvalue=cl_equal_hashcode(*value) | 0x80000000U);
- /*
- cout << *value << "->" << hashvalue << endl;
- hashvalue=HASHVALUE_NUMERIC+1000U;
- return HASHVALUE_NUMERIC+1000U;
- */
-}
-/*
unsigned numeric::calchash(void) const
{
- double d=to_double();
- int s=d>0 ? 1 : -1;
- d=fabs(d);
- if (d>0x07FF0000) {
- d=0x07FF0000;
- }
- return 0x88000000U+s*unsigned(d/0x07FF0000);
+ // Use CLN's hashcode. Warning: It depends only on the number's value, not
+ // its type or precision (i.e. a true equivalence relation on numbers). As
+ // a consequence, 3 and 3.0 share the same hashvalue.
+ return (hashvalue = cl_equal_hashcode(*value) | 0x80000000U);
}
-*/
//////////
// Comparing two real numbers?
if (this->is_real() && other.is_real())
// Yes, just compare them
- return ::cl_compare(The(cl_R)(*value), The(cl_R)(*other.value));
+ return ::cl_compare(The(::cl_R)(*value), The(::cl_R)(*other.value));
else {
// No, first compare real parts
cl_signean real_cmp = ::cl_compare(::realpart(*value), ::realpart(*other.value));
bool numeric::is_positive(void) const
{
if (this->is_real())
- return ::plusp(The(cl_R)(*value)); // -> CLN
+ return ::plusp(The(::cl_R)(*value)); // -> CLN
return false;
}
bool numeric::is_negative(void) const
{
if (this->is_real())
- return ::minusp(The(cl_R)(*value)); // -> CLN
+ return ::minusp(The(::cl_R)(*value)); // -> CLN
return false;
}
/** True if object is an exact integer greater than zero. */
bool numeric::is_pos_integer(void) const
{
- return (this->is_integer() && ::plusp(The(cl_I)(*value))); // -> CLN
+ return (this->is_integer() && ::plusp(The(::cl_I)(*value))); // -> CLN
}
/** True if object is an exact integer greater or equal zero. */
bool numeric::is_nonneg_integer(void) const
{
- return (this->is_integer() && !::minusp(The(cl_I)(*value))); // -> CLN
+ return (this->is_integer() && !::minusp(The(::cl_I)(*value))); // -> CLN
}
/** True if object is an exact even integer. */
bool numeric::is_even(void) const
{
- return (this->is_integer() && ::evenp(The(cl_I)(*value))); // -> CLN
+ return (this->is_integer() && ::evenp(The(::cl_I)(*value))); // -> CLN
}
/** True if object is an exact odd integer. */
bool numeric::is_odd(void) const
{
- return (this->is_integer() && ::oddp(The(cl_I)(*value))); // -> CLN
+ return (this->is_integer() && ::oddp(The(::cl_I)(*value))); // -> CLN
}
/** Probabilistic primality test.
* @return true if object is exact integer and prime. */
bool numeric::is_prime(void) const
{
- return (this->is_integer() && ::isprobprime(The(cl_I)(*value))); // -> CLN
+ return (this->is_integer() && ::isprobprime(The(::cl_I)(*value))); // -> CLN
}
/** True if object is an exact rational number, may even be complex
bool numeric::operator<(const numeric & other) const
{
if (this->is_real() && other.is_real())
- return (The(cl_R)(*value) < The(cl_R)(*other.value)); // -> CLN
+ return (The(::cl_R)(*value) < The(::cl_R)(*other.value)); // -> CLN
throw (std::invalid_argument("numeric::operator<(): complex inequality"));
return false; // make compiler shut up
}
bool numeric::operator<=(const numeric & other) const
{
if (this->is_real() && other.is_real())
- return (The(cl_R)(*value) <= The(cl_R)(*other.value)); // -> CLN
+ return (The(::cl_R)(*value) <= The(::cl_R)(*other.value)); // -> CLN
throw (std::invalid_argument("numeric::operator<=(): complex inequality"));
return false; // make compiler shut up
}
bool numeric::operator>(const numeric & other) const
{
if (this->is_real() && other.is_real())
- return (The(cl_R)(*value) > The(cl_R)(*other.value)); // -> CLN
+ return (The(::cl_R)(*value) > The(::cl_R)(*other.value)); // -> CLN
throw (std::invalid_argument("numeric::operator>(): complex inequality"));
return false; // make compiler shut up
}
bool numeric::operator>=(const numeric & other) const
{
if (this->is_real() && other.is_real())
- return (The(cl_R)(*value) >= The(cl_R)(*other.value)); // -> CLN
+ return (The(::cl_R)(*value) >= The(::cl_R)(*other.value)); // -> CLN
throw (std::invalid_argument("numeric::operator>=(): complex inequality"));
return false; // make compiler shut up
}
int numeric::to_int(void) const
{
GINAC_ASSERT(this->is_integer());
- return ::cl_I_to_int(The(cl_I)(*value)); // -> CLN
+ return ::cl_I_to_int(The(::cl_I)(*value)); // -> CLN
}
/** Converts numeric types to machine's long. You should check with
long numeric::to_long(void) const
{
GINAC_ASSERT(this->is_integer());
- return ::cl_I_to_long(The(cl_I)(*value)); // -> CLN
+ return ::cl_I_to_long(The(::cl_I)(*value)); // -> CLN
}
/** Converts numeric types to machine's double. You should check with is_real()
}
#ifdef SANE_LINKER
else if (::instanceof(*value, ::cl_RA_ring)) {
- return numeric(::numerator(The(cl_RA)(*value)));
+ return numeric(::numerator(The(::cl_RA)(*value)));
}
else if (!this->is_real()) { // complex case, handle Q(i):
cl_R r = ::realpart(*value);
if (::instanceof(r, ::cl_I_ring) && ::instanceof(i, ::cl_I_ring))
return numeric(*this);
if (::instanceof(r, ::cl_I_ring) && ::instanceof(i, ::cl_RA_ring))
- return numeric(::complex(r*::denominator(The(cl_RA)(i)), ::numerator(The(cl_RA)(i))));
+ return numeric(::complex(r*::denominator(The(::cl_RA)(i)), ::numerator(The(::cl_RA)(i))));
if (::instanceof(r, ::cl_RA_ring) && ::instanceof(i, ::cl_I_ring))
- return numeric(::complex(::numerator(The(cl_RA)(r)), i*::denominator(The(cl_RA)(r))));
+ return numeric(::complex(::numerator(The(::cl_RA)(r)), i*::denominator(The(::cl_RA)(r))));
if (::instanceof(r, ::cl_RA_ring) && ::instanceof(i, ::cl_RA_ring)) {
- cl_I s = ::lcm(::denominator(The(cl_RA)(r)), ::denominator(The(cl_RA)(i)));
- return numeric(::complex(::numerator(The(cl_RA)(r))*(exquo(s,::denominator(The(cl_RA)(r)))),
- ::numerator(The(cl_RA)(i))*(exquo(s,::denominator(The(cl_RA)(i))))));
+ cl_I s = ::lcm(::denominator(The(::cl_RA)(r)), ::denominator(The(::cl_RA)(i)));
+ return numeric(::complex(::numerator(The(::cl_RA)(r))*(exquo(s,::denominator(The(::cl_RA)(r)))),
+ ::numerator(The(::cl_RA)(i))*(exquo(s,::denominator(The(::cl_RA)(i))))));
}
}
#else
}
#ifdef SANE_LINKER
if (instanceof(*value, ::cl_RA_ring)) {
- return numeric(::denominator(The(cl_RA)(*value)));
+ return numeric(::denominator(The(::cl_RA)(*value)));
}
if (!this->is_real()) { // complex case, handle Q(i):
cl_R r = ::realpart(*value);
if (::instanceof(r, ::cl_I_ring) && ::instanceof(i, ::cl_I_ring))
return _num1();
if (::instanceof(r, ::cl_I_ring) && ::instanceof(i, ::cl_RA_ring))
- return numeric(::denominator(The(cl_RA)(i)));
+ return numeric(::denominator(The(::cl_RA)(i)));
if (::instanceof(r, ::cl_RA_ring) && ::instanceof(i, ::cl_I_ring))
- return numeric(::denominator(The(cl_RA)(r)));
+ return numeric(::denominator(The(::cl_RA)(r)));
if (::instanceof(r, ::cl_RA_ring) && ::instanceof(i, ::cl_RA_ring))
- return numeric(::lcm(::denominator(The(cl_RA)(r)), ::denominator(The(cl_RA)(i))));
+ return numeric(::lcm(::denominator(The(::cl_RA)(r)), ::denominator(The(::cl_RA)(i))));
}
#else
if (instanceof(*value, ::cl_RA_ring)) {
int numeric::int_length(void) const
{
if (this->is_integer())
- return ::integer_length(The(cl_I)(*value)); // -> CLN
+ return ::integer_length(The(::cl_I)(*value)); // -> CLN
else
return 0;
}
}
}
- // should really be gamma(n+1)/(gamma(r+1)/gamma(n-r+1) or a suitable limit
+ // should really be gamma(n+1)/gamma(r+1)/gamma(n-r+1) or a suitable limit
throw (std::range_error("numeric::binomial(): don´t know how to evaluate that."));
}
{
if (!nn.is_integer() || nn.is_negative())
throw (std::range_error("numeric::bernoulli(): argument must be integer >= 0"));
- if (nn.is_zero())
- return _num1();
+
+ // Method:
+ //
+ // The Bernoulli numbers are rational numbers that may be computed using
+ // the relation
+ //
+ // B_n = - 1/(n+1) * sum_{k=0}^{n-1}(binomial(n+1,k)*B_k)
+ //
+ // with B(0) = 1. Since the n'th Bernoulli number depends on all the
+ // previous ones, the computation is necessarily very expensive. There are
+ // several other ways of computing them, a particularly good one being
+ // cl_I s = 1;
+ // cl_I c = n+1;
+ // cl_RA Bern = 0;
+ // for (unsigned i=0; i<n; i++) {
+ // c = exquo(c*(i-n),(i+2));
+ // Bern = Bern + c*s/(i+2);
+ // s = s + expt_pos(cl_I(i+2),n);
+ // }
+ // return Bern;
+ //
+ // But if somebody works with the n'th Bernoulli number she is likely to
+ // also need all previous Bernoulli numbers. So we need a complete remember
+ // table and above divide and conquer algorithm is not suited to build one
+ // up. The code below is adapted from Pari's function bernvec().
+ //
+ // (There is an interesting relation with the tangent polynomials described
+ // in `Concrete Mathematics', which leads to a program twice as fast as our
+ // implementation below, but it requires storing one such polynomial in
+ // addition to the remember table. This doubles the memory footprint so
+ // we don't use it.)
+
+ // the special cases not covered by the algorithm below
if (!nn.compare(_num1()))
return numeric(-1,2);
if (nn.is_odd())
return _num0();
- // Until somebody has the blues and comes up with a much better idea and
- // codes it (preferably in CLN) we make this a remembering function which
- // computes its results using the defining formula
- // B(nn) == - 1/(nn+1) * sum_{k=0}^{nn-1}(binomial(nn+1,k)*B(k))
- // whith B(0) == 1.
- // Be warned, though: the Bernoulli numbers are computationally very
- // expensive anyhow and you shouldn't expect miracles to happen.
- static vector<numeric> results;
- static int highest_result = -1;
- int n = nn.sub(_num2()).div(_num2()).to_int();
- if (n <= highest_result)
- return results[n];
- if (results.capacity() < (unsigned)(n+1))
- results.reserve(n+1);
- numeric tmp; // used to store the sum
- for (int i=highest_result+1; i<=n; ++i) {
- // the first two elements:
- tmp = numeric(-2*i-1,2);
- // accumulate the remaining elements:
- for (int j=0; j<i; ++j)
- tmp += binomial(numeric(2*i+3),numeric(j*2+2))*results[j];
- // divide by -(nn+1) and store result:
- results.push_back(-tmp/numeric(2*i+3));
+ // store nonvanishing Bernoulli numbers here
+ static vector< ::cl_RA > results;
+ static int highest_result = 0;
+ // algorithm not applicable to B(0), so just store it
+ if (results.size()==0)
+ results.push_back(::cl_RA(1));
+
+ int n = nn.to_long();
+ for (int i=highest_result; i<n/2; ++i) {
+ ::cl_RA B = 0;
+ long n = 8;
+ long m = 5;
+ long d1 = i;
+ long d2 = 2*i-1;
+ for (int j=i; j>0; --j) {
+ B = cl_I(n*m) * (B+results[j]) / (d1*d2);
+ n += 4;
+ m += 2;
+ d1 -= 1;
+ d2 -= 2;
+ }
+ B = (1 - ((B+1)/(2*i+3))) / (cl_I(1)<<(2*i+2));
+ results.push_back(B);
+ ++highest_result;
}
- highest_result=n;
- return results[n];
+ return results[n/2];
}
{
if (!n.is_integer())
throw (std::range_error("numeric::fibonacci(): argument must be integer"));
+ // Method:
+ //
+ // This is based on an implementation that can be found in CLN's example
+ // directory. There, it is done recursively, which may be more elegant
+ // than our non-recursive implementation that has to resort to some bit-
+ // fiddling. This is, however, a matter of taste.
// The following addition formula holds:
+ //
// F(n+m) = F(m-1)*F(n) + F(m)*F(n+1) for m >= 1, n >= 0.
+ //
// (Proof: For fixed m, the LHS and the RHS satisfy the same recurrence
// w.r.t. n, and the initial values (n=0, n=1) agree. Hence all values
// agree.)
else
return fibonacci(-n);
- cl_I u(0);
- cl_I v(1);
- cl_I m = The(cl_I)(*n.value) >> 1L; // floor(n/2);
+ ::cl_I u(0);
+ ::cl_I v(1);
+ ::cl_I m = The(::cl_I)(*n.value) >> 1L; // floor(n/2);
for (uintL bit=::integer_length(m); bit>0; --bit) {
// Since a squaring is cheaper than a multiplication, better use
// three squarings instead of one multiplication and two squarings.
- cl_I u2 = ::square(u);
- cl_I v2 = ::square(v);
+ ::cl_I u2 = ::square(u);
+ ::cl_I v2 = ::square(v);
if (::logbitp(bit-1, m)) {
v = ::square(u + v) - u2;
u = u2 + v2;
numeric mod(const numeric & a, const numeric & b)
{
if (a.is_integer() && b.is_integer())
- return ::mod(The(cl_I)(*a.value), The(cl_I)(*b.value)); // -> CLN
+ return ::mod(The(::cl_I)(*a.value), The(::cl_I)(*b.value)); // -> CLN
else
return _num0(); // Throw?
}
numeric smod(const numeric & a, const numeric & b)
{
if (a.is_integer() && b.is_integer()) {
- cl_I b2 = The(cl_I)(ceiling1(The(cl_I)(*b.value) / 2)) - 1;
- return ::mod(The(cl_I)(*a.value) + b2, The(cl_I)(*b.value)) - b2;
+ cl_I b2 = The(::cl_I)(ceiling1(The(::cl_I)(*b.value) / 2)) - 1;
+ return ::mod(The(::cl_I)(*a.value) + b2, The(::cl_I)(*b.value)) - b2;
} else
return _num0(); // Throw?
}
numeric irem(const numeric & a, const numeric & b)
{
if (a.is_integer() && b.is_integer())
- return ::rem(The(cl_I)(*a.value), The(cl_I)(*b.value)); // -> CLN
+ return ::rem(The(::cl_I)(*a.value), The(::cl_I)(*b.value)); // -> CLN
else
return _num0(); // Throw?
}
numeric irem(const numeric & a, const numeric & b, numeric & q)
{
if (a.is_integer() && b.is_integer()) { // -> CLN
- cl_I_div_t rem_quo = truncate2(The(cl_I)(*a.value), The(cl_I)(*b.value));
+ cl_I_div_t rem_quo = truncate2(The(::cl_I)(*a.value), The(::cl_I)(*b.value));
q = rem_quo.quotient;
return rem_quo.remainder;
}
numeric iquo(const numeric & a, const numeric & b)
{
if (a.is_integer() && b.is_integer())
- return truncate1(The(cl_I)(*a.value), The(cl_I)(*b.value)); // -> CLN
+ return truncate1(The(::cl_I)(*a.value), The(::cl_I)(*b.value)); // -> CLN
else
return _num0(); // Throw?
}
numeric iquo(const numeric & a, const numeric & b, numeric & r)
{
if (a.is_integer() && b.is_integer()) { // -> CLN
- cl_I_div_t rem_quo = truncate2(The(cl_I)(*a.value), The(cl_I)(*b.value));
+ cl_I_div_t rem_quo = truncate2(The(::cl_I)(*a.value), The(::cl_I)(*b.value));
r = rem_quo.remainder;
return rem_quo.quotient;
} else {
{
if (x.is_integer()) {
cl_I root;
- ::isqrt(The(cl_I)(*x.value), &root); // -> CLN
+ ::isqrt(The(::cl_I)(*x.value), &root); // -> CLN
return root;
} else
return _num0(); // Throw?
numeric gcd(const numeric & a, const numeric & b)
{
if (a.is_integer() && b.is_integer())
- return ::gcd(The(cl_I)(*a.value), The(cl_I)(*b.value)); // -> CLN
+ return ::gcd(The(::cl_I)(*a.value), The(::cl_I)(*b.value)); // -> CLN
else
return _num1();
}
numeric lcm(const numeric & a, const numeric & b)
{
if (a.is_integer() && b.is_integer())
- return ::lcm(The(cl_I)(*a.value), The(cl_I)(*b.value)); // -> CLN
+ return ::lcm(The(::cl_I)(*a.value), The(::cl_I)(*b.value)); // -> CLN
else
return *a.value * *b.value;
}
/** Floating point evaluation of Euler's constant gamma. */
-ex gammaEvalf(void)
+ex EulerEvalf(void)
{
return numeric(::cl_eulerconst(cl_default_float_format)); // -> CLN
}
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