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 int cf_sign(cf_t cf);
  18 int cf_flip_sign(cf_t cf);
  19 void cf_get(mpz_t z, cf_t cf);
  20 void cf_put(cf_t cf, mpz_t z);
  21 void cf_put_int(cf_t cf, int n);
  22
  23 int cf_wait(cf_t cf);
  24
  25 void *cf_data(cf_t cf);
  26
  27 // cf_mobius.c:
  28 // Compute convergents of a simple continued fraction x.
  29 // Outputs p then q on channel, where p/q is the last convergent computed.
  30 cf_t cf_new_convergent(cf_t x);
  31
  32 // Compute convergents of (a x + b)/(c x + d)
  33 // where x is a regular continued fraction.
  34 cf_t cf_new_mobius_convergent(cf_t x, mpz_t a, mpz_t b, mpz_t c, mpz_t d);
  35
  36 // Compute convergents of (a x + b)/(c x + d)
  37 // where x is a nonregular continued fraction.
  38 cf_t cf_new_nonregular_mobius_convergent(cf_t x, mpz_t a, mpz_t b, mpz_t c, mpz_t d);
  39
  40 cf_t cf_new_nonregular_to_cf(cf_t x, mpz_t a, mpz_t b, mpz_t c, mpz_t d);
  41
  42 cf_t cf_new_mobius_to_decimal(cf_t x, mpz_t a, mpz_t b, mpz_t c, mpz_t d);
  43 cf_t cf_new_cf_to_decimal(cf_t x);
  44 cf_t cf_new_nonregular_mobius_to_decimal(cf_t x, mpz_t a, mpz_t b, mpz_t c, mpz_t d);
  45
  46 // Well-known continued fraction expansions.
  47 // cf_famous.c:
  48 // e:
  49 cf_t cf_new_e();
  50 cf_t cf_new_pi();
  51 cf_t cf_new_tan1();
  52 cf_t cf_new_epow(mpz_t pow);
  53 cf_t cf_new_tanh(mpz_t z);
  54
  55 // This won't work because my code cannot handle negative denominators,
  56 // and also assumes the sequence of convergents alternatively overshoot
  57 // and undershoots the target. The tan expansion leads to a sequence of
  58 // strictly increasing convergents (for positive input).
  59 cf_t cf_new_tan(mpz_t z);
  60
  61 // Gosper's method for computing bihomographic functions of continued fractions.
  62 cf_t cf_new_bihom(cf_t x, cf_t y, mpz_t a[8]);
  63
  64 // From taylor.c:
  65 cf_t cf_new_sin1();
  66 cf_t cf_new_cos1();
  67
  68 #endif  // __CF_H__