genfun.cc

   1 #include <iostream>
   2 #include <assert.h>
   3 #include <genfun.h>
   4
   5 using std::cout;
   6
   7 static int lex_cmp(vec_ZZ& a, vec_ZZ& b)
   8 {
   9     assert(a.length() == b.length());
  10
  11     for (int j = 0; j < a.length(); ++j)
  12         if (a[j] != b[j])
  13             return a[j] < b[j] ? -1 : 1;
  14     return 0;
  15 }
  16
  17 static int lex_cmp(mat_ZZ& a, mat_ZZ& b)
  18 {
  19     assert(a.NumCols() == b.NumCols());
  20     int alen = a.NumRows();
  21     int blen = b.NumRows();
  22     int len = alen < blen ? alen : blen;
  23
  24     for (int i = 0; i < len; ++i) {
  25         int s = lex_cmp(a[i], b[i]);
  26         if (s)
  27             return s;
  28     }
  29     return alen-blen;
  30 }
  31
  32 void gen_fun::add(ZZ& cn, ZZ& cd, vec_ZZ& num, mat_ZZ& den)
  33 {
  34     if (cn == 0)
  35         return;
  36
  37     short_rat * r = new short_rat;
  38     r->n.coeff.SetDims(1, 2);
  39     r->n.coeff[0][0] = cn;
  40     r->n.coeff[0][1] = cd;
  41     r->n.power.SetDims(1, num.length());
  42     r->n.power[0] = num;
  43     r->d.power = den;
  44
  45     for (int i = 0; i < r->d.power.NumRows(); ++i) {
  46         int j;
  47         for (j = 0; j < r->d.power.NumCols(); ++j)
  48             if (r->d.power[i][j] != 0)
  49                 break;
  50         if (r->d.power[i][j] < 0) {
  51             r->d.power[i] = -r->d.power[i];
  52             r->n.coeff[0][0] = -r->n.coeff[0][0];
  53             r->n.power[0] += r->d.power[i];
  54         }
  55     }
  56
  57     for (int i = 0; i < term.size(); ++i)
  58         if (lex_cmp(term[i]->d.power, r->d.power) == 0) {
  59             int len = term[i]->n.coeff.NumRows();
  60             int dim = term[i]->n.power.NumCols();
  61             term[i]->n.coeff.SetDims(len+1, 2);
  62             term[i]->n.power.SetDims(len+1, dim);
  63             term[i]->n.coeff[len] = r->n.coeff[0];
  64             term[i]->n.power[len] = r->n.power[0];
  65             delete r;
  66             return;
  67         }
  68
  69     term.push_back(r);
  70 }
  71
  72 static void print_power(vec_ZZ& c, vec_ZZ& p,
  73                         unsigned int nparam, char **param_name)
  74 {
  75     bool first = true;
  76
  77     for (int i = 0; i < p.length(); ++i) {
  78         if (p[i] == 0)
  79             continue;
  80         if (first) {
  81             if (c[0] == -1 && c[1] == 1)
  82                 cout << "-";
  83             else if (c[0] != 1 || c[1] != 1) {
  84                 cout << c[0];
  85                 if (c[1] != 1)
  86                     cout << " / " << c[1];
  87                 cout << " * ";
  88             }
  89             first = false;
  90         } else
  91             cout << " * ";
  92         if (i < nparam)
  93             cout << param_name[i];
  94         else
  95             cout << "x" << i;
  96         if (p[i] == 1)
  97             continue;
  98         if (p[i] < 0)
  99             cout << "^(" << p[i] << ")";
 100         else
 101             cout << "^" << p[i];
 102     }
 103     if (first) {
 104         cout << c[0];
 105         if (c[1] != 1)
 106             cout << " / " << c[1];
 107     }
 108 }
 109
 110 void gen_fun::print(unsigned int nparam, char **param_name)
 111 {
 112     vec_ZZ mone;
 113     mone.SetLength(1);
 114     mone[0] = -1;
 115     mone[1] = 1;
 116     for (int i = 0; i < term.size(); ++i) {
 117         if (i != 0)
 118             cout << " + ";
 119         cout << "(";
 120         for (int j = 0; j < term[i]->n.coeff.NumRows(); ++j) {
 121             if (j != 0 && term[i]->n.coeff[j][0] > 0)
 122                 cout << "+";
 123             print_power(term[i]->n.coeff[j], term[i]->n.power[j],
 124                         nparam, param_name);
 125         }
 126         cout << ")/(";
 127         for (int j = 0; j < term[i]->d.power.NumRows(); ++j) {
 128             if (j != 0)
 129                 cout << " * ";
 130             cout << "(1";
 131             print_power(mone, term[i]->d.power[j],
 132                         nparam, param_name);
 133             cout << ")";
 134         }
 135         cout << ")";
 136     }
 137 }