cf.h

   1 // Requires gmp.h
   2 //
   3 // Opaque interface to continued fractions object.
   4
   5 #ifndef __CF_H__
   6 #define __CF_H__
   7
   8 struct cf_s;
   9 typedef struct cf_s *cf_t;
  10
  11 cf_t cf_new(void *(*func)(cf_t), void *data);
  12 static inline cf_t cf_new_const(void *(*func)(cf_t)) {
  13   return cf_new(func, NULL);
  14 }
  15 void cf_free(cf_t cf);
  16
  17 void cf_get(mpz_t z, cf_t cf);
  18 void cf_put(cf_t cf, mpz_t z);
  19 void cf_put_int(cf_t cf, int n);
  20
  21 int cf_wait(cf_t cf);
  22
  23 void *cf_data(cf_t cf);
  24
  25 // cf_mobius.c:
  26 // Compute convergents of a simple continued fraction x.
  27 // Outputs p then q on channel, where p/q is the last convergent computed.
  28 cf_t cf_new_convergent(cf_t x);
  29
  30 // Compute convergents of (a x + b)/(c x + d)
  31 // where x is a regular continued fraction.
  32 cf_t cf_new_mobius_convergent(cf_t x, mpz_t a, mpz_t b, mpz_t c, mpz_t d);
  33
  34 // Compute convergents of (a x + b)/(c x + d)
  35 // where x is a nonregular continued fraction.
  36 cf_t cf_new_nonregular_mobius_convergent(cf_t x, mpz_t a, mpz_t b, mpz_t c, mpz_t d);
  37
  38 cf_t cf_new_nonregular_to_cf(cf_t x, mpz_t a, mpz_t b, mpz_t c, mpz_t d);
  39
  40 cf_t cf_new_mobius_to_decimal(cf_t x, mpz_t a, mpz_t b, mpz_t c, mpz_t d);
  41 cf_t cf_new_cf_to_decimal(cf_t x);
  42 cf_t cf_new_nonregular_mobius_to_decimal(cf_t x, mpz_t a, mpz_t b, mpz_t c, mpz_t d);
  43
  44 // Well-known continued fraction expansions.
  45 // cf_famous.c:
  46 // e:
  47 cf_t cf_new_e();
  48 cf_t cf_new_pi();
  49 cf_t cf_new_tan1();
  50 cf_t cf_new_epow(mpz_t pow);
  51 cf_t cf_new_tanh(mpz_t z);
  52
  53 // This won't work because my code cannot handle negative denominators,
  54 // and also assumes the sequence of convergents alternatively overshoot
  55 // and undershoots the target. The tan expansion leads to a sequence of
  56 // strictly increasing convergents (for positive input).
  57 cf_t cf_new_tan(mpz_t z);
  58
  59 // Gosper's method for computing bihomographic functions of continued fractions.
  60 cf_t cf_new_bihom(cf_t x, cf_t y, mpz_t a[8]);
  61
  62 // From taylor.c:
  63 cf_t cf_new_sin1();
  64 cf_t cf_new_cos1();
  65
  66 #endif  // __CF_H__