]> www.ginac.de Git - ginac.git/blobdiff - ginac/numeric.cpp
documentation update
[ginac.git] / ginac / numeric.cpp
index 5c8f65061819933dd37751ccf89cf5281628a67b..1d4de9f5b416d4e997f6d590f0c96ef7edb57e4c 100644 (file)
@@ -30,6 +30,7 @@
 #include <stdexcept>
 #include <string>
 #include <sstream>
+#include <limits>
 
 #include "numeric.h"
 #include "ex.h"
@@ -94,10 +95,10 @@ numeric::numeric(int i) : basic(TINFO_numeric)
        // emphasizes efficiency.  However, if the integer is small enough
        // we save space and dereferences by using an immediate type.
        // (C.f. <cln/object.h>)
-       if (i < (1U<<cl_value_len-1))
+       if (i < (1L << (cl_value_len-1)) && i >= -(1L << (cl_value_len-1)))
                value = cln::cl_I(i);
        else
-               value = cln::cl_I((long) i);
+               value = cln::cl_I(static_cast<long>(i));
        setflag(status_flags::evaluated | status_flags::expanded);
 }
 
@@ -109,10 +110,10 @@ numeric::numeric(unsigned int i) : basic(TINFO_numeric)
        // emphasizes efficiency.  However, if the integer is small enough
        // we save space and dereferences by using an immediate type.
        // (C.f. <cln/object.h>)
-       if (i < (1U<<cl_value_len-1))
+       if (i < (1U << (cl_value_len-1)))
                value = cln::cl_I(i);
        else
-               value = cln::cl_I((unsigned long) i);
+               value = cln::cl_I(static_cast<unsigned long>(i));
        setflag(status_flags::evaluated | status_flags::expanded);
 }
 
@@ -130,7 +131,8 @@ numeric::numeric(unsigned long i) : basic(TINFO_numeric)
        setflag(status_flags::evaluated | status_flags::expanded);
 }
 
-/** Ctor for rational numerics a/b.
+
+/** Constructor for rational numerics a/b.
  *
  *  @exception overflow_error (division by zero) */
 numeric::numeric(long numer, long denom) : basic(TINFO_numeric)
@@ -243,7 +245,7 @@ numeric::numeric(const cln::cl_N &z) : basic(TINFO_numeric)
 // archiving
 //////////
 
-numeric::numeric(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst)
+numeric::numeric(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
 {
        cln::cl_N ctorval = 0;
 
@@ -314,7 +316,7 @@ DEFAULT_UNARCHIVE(numeric)
  *  want to visibly distinguish from cl_LF.
  *
  *  @see numeric::print() */
-static void print_real_number(const print_context & c, const cln::cl_R &x)
+static void print_real_number(const print_context & c, const cln::cl_R & x)
 {
        cln::cl_print_flags ourflags;
        if (cln::instanceof(x, cln::cl_RA_ring)) {
@@ -340,6 +342,82 @@ static void print_real_number(const print_context & c, const cln::cl_R &x)
        }
 }
 
+/** Helper function to print integer number in C++ source format.
+ *
+ *  @see numeric::print() */
+static void print_integer_csrc(const print_context & c, const cln::cl_I & x)
+{
+       // Print small numbers in compact float format, but larger numbers in
+       // scientific format
+       const int max_cln_int = 536870911; // 2^29-1
+       if (x >= cln::cl_I(-max_cln_int) && x <= cln::cl_I(max_cln_int))
+               c.s << cln::cl_I_to_int(x) << ".0";
+       else
+               c.s << cln::double_approx(x);
+}
+
+/** Helper function to print real number in C++ source format.
+ *
+ *  @see numeric::print() */
+static void print_real_csrc(const print_context & c, const cln::cl_R & x)
+{
+       if (cln::instanceof(x, cln::cl_I_ring)) {
+
+               // Integer number
+               print_integer_csrc(c, cln::the<cln::cl_I>(x));
+
+       } else if (cln::instanceof(x, cln::cl_RA_ring)) {
+
+               // Rational number
+               const cln::cl_I numer = cln::numerator(cln::the<cln::cl_RA>(x));
+               const cln::cl_I denom = cln::denominator(cln::the<cln::cl_RA>(x));
+               if (cln::plusp(x) > 0) {
+                       c.s << "(";
+                       print_integer_csrc(c, numer);
+               } else {
+                       c.s << "-(";
+                       print_integer_csrc(c, -numer);
+               }
+               c.s << "/";
+               print_integer_csrc(c, denom);
+               c.s << ")";
+
+       } else {
+
+               // Anything else
+               c.s << cln::double_approx(x);
+       }
+}
+
+/** Helper function to print real number in C++ source format using cl_N types.
+ *
+ *  @see numeric::print() */
+static void print_real_cl_N(const print_context & c, const cln::cl_R & x)
+{
+       if (cln::instanceof(x, cln::cl_I_ring)) {
+
+               // Integer number
+               c.s << "cln::cl_I(\"";
+               print_real_number(c, x);
+               c.s << "\")";
+
+       } else if (cln::instanceof(x, cln::cl_RA_ring)) {
+
+               // Rational number
+               cln::cl_print_flags ourflags;
+               c.s << "cln::cl_RA(\"";
+               cln::print_rational(c.s, ourflags, cln::the<cln::cl_RA>(x));
+               c.s << "\")";
+
+       } else {
+
+               // Anything else
+               c.s << "cln::cl_F(\"";
+               print_real_number(c, cln::cl_float(1.0, cln::default_float_format) * x);
+               c.s << "_" << Digits << "\")";
+       }
+}
+
 /** This method adds to the output so it blends more consistently together
  *  with the other routines and produces something compatible to ginsh input.
  *  
@@ -353,56 +431,69 @@ void numeric::print(const print_context & c, unsigned level) const
                    << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
                    << std::endl;
 
+       } else if (is_a<print_csrc_cl_N>(c)) {
+
+               // CLN output
+               if (this->is_real()) {
+
+                       // Real number
+                       print_real_cl_N(c, cln::the<cln::cl_R>(value));
+
+               } else {
+
+                       // Complex number
+                       c.s << "cln::complex(";
+                       print_real_cl_N(c, cln::realpart(cln::the<cln::cl_N>(value)));
+                       c.s << ",";
+                       print_real_cl_N(c, cln::imagpart(cln::the<cln::cl_N>(value)));
+                       c.s << ")";
+               }
+
        } else if (is_a<print_csrc>(c)) {
 
+               // C++ source output
                std::ios::fmtflags oldflags = c.s.flags();
                c.s.setf(std::ios::scientific);
                int oldprec = c.s.precision();
+
+               // Set precision
                if (is_a<print_csrc_double>(c))
-                       c.s.precision(16);
+                       c.s.precision(std::numeric_limits<double>::digits10 + 1);
                else
-                       c.s.precision(7);
-               if (is_a<print_csrc_cl_N>(c) && this->is_integer()) {
-                       c.s << "cln::cl_I(\"";
-                       const cln::cl_R r = cln::realpart(cln::the<cln::cl_N>(value));
-                       print_real_number(c,r);
-                       c.s << "\")";
-               } else if (this->is_rational() && !this->is_integer()) {
-                       if (compare(_num0) > 0) {
-                               c.s << "(";
-                               if (is_a<print_csrc_cl_N>(c))
-                                       c.s << "cln::cl_F(\"" << numer().evalf() << "\")";
-                               else
-                                       c.s << numer().to_double();
-                       } else {
-                               c.s << "-(";
-                               if (is_a<print_csrc_cl_N>(c))
-                                       c.s << "cln::cl_F(\"" << -numer().evalf() << "\")";
-                               else
-                                       c.s << -numer().to_double();
-                       }
-                       c.s << "/";
-                       if (is_a<print_csrc_cl_N>(c))
-                               c.s << "cln::cl_F(\"" << denom().evalf() << "\")";
-                       else
-                               c.s << denom().to_double();
-                       c.s << ")";
+                       c.s.precision(std::numeric_limits<float>::digits10 + 1);
+
+               if (this->is_real()) {
+
+                       // Real number
+                       print_real_csrc(c, cln::the<cln::cl_R>(value));
+
                } else {
-                       if (is_a<print_csrc_cl_N>(c))
-                               c.s << "cln::cl_F(\"" << evalf() << "_" << Digits << "\")";
+
+                       // Complex number
+                       c.s << "std::complex<";
+                       if (is_a<print_csrc_double>(c))
+                               c.s << "double>(";
                        else
-                               c.s << to_double();
+                               c.s << "float>(";
+
+                       print_real_csrc(c, cln::realpart(cln::the<cln::cl_N>(value)));
+                       c.s << ",";
+                       print_real_csrc(c, cln::imagpart(cln::the<cln::cl_N>(value)));
+                       c.s << ")";
                }
+
                c.s.flags(oldflags);
                c.s.precision(oldprec);
 
        } else {
+
                const std::string par_open  = is_a<print_latex>(c) ? "{(" : "(";
                const std::string par_close = is_a<print_latex>(c) ? ")}" : ")";
                const std::string imag_sym  = is_a<print_latex>(c) ? "i" : "I";
                const std::string mul_sym   = is_a<print_latex>(c) ? " " : "*";
                const cln::cl_R r = cln::realpart(cln::the<cln::cl_N>(value));
                const cln::cl_R i = cln::imagpart(cln::the<cln::cl_N>(value));
+
                if (is_a<print_python_repr>(c))
                        c.s << class_name() << "('";
                if (cln::zerop(i)) {
@@ -667,8 +758,9 @@ const numeric numeric::div(const numeric &other) const
  *  returns result as a numeric object. */
 const numeric numeric::power(const numeric &other) const
 {
-       // Efficiency shortcut: trap the neutral exponent by pointer.
-       if (&other==_num1_p)
+       // Shortcut for efficiency and numeric stability (as in 1.0 exponent):
+       // trap the neutral exponent.
+       if (&other==_num1_p || cln::equal(cln::the<cln::cl_N>(other.value),cln::the<cln::cl_N>(_num1.value)))
                return *this;
        
        if (cln::zerop(cln::the<cln::cl_N>(value))) {
@@ -691,7 +783,8 @@ const numeric numeric::power(const numeric &other) const
  *  an ex object, where the result would end up on the heap anyways. */
 const numeric &numeric::add_dyn(const numeric &other) const
 {
-       // Efficiency shortcut: trap the neutral element by pointer.
+       // Efficiency shortcut: trap the neutral element by pointer.  This hack
+       // is supposed to keep the number of distinct numeric objects low.
        if (this==_num0_p)
                return other;
        else if (&other==_num0_p)
@@ -751,8 +844,10 @@ const numeric &numeric::div_dyn(const numeric &other) const
  *  heap anyways. */
 const numeric &numeric::power_dyn(const numeric &other) const
 {
-       // Efficiency shortcut: trap the neutral exponent by pointer.
-       if (&other==_num1_p)
+       // Efficiency shortcut: trap the neutral exponent (first try by pointer, then
+       // try harder, since calls to cln::expt() below may return amazing results for
+       // floating point exponent 1.0).
+       if (&other==_num1_p || cln::equal(cln::the<cln::cl_N>(other.value),cln::the<cln::cl_N>(_num1.value)))
                return *this;
        
        if (cln::zerop(cln::the<cln::cl_N>(value))) {