trigonometric functions

[Torbjorn Granlund]

Sara Costa <scosta at mat.uab.es> writes:

  I am doing my PhD in Mathematics and I am starting to use gmp because I
  need to compute some thing with a lot of precision. What I have to do is
  to iterate many many times a map, usually a multidimensional map. The
  trouble, after reading the manual, I find is that in the the
  trigonometric fuctions, or at least one of them (e.g. the cosinus of a
  number) is not in the library. The hiperbolic trigonometric functions
  are not a problem because they are defined in terms of the exponential
  of the number. The same happens with the logarith, but about this
  particular I have to read carefully the manual, because if there is any
  way to compute it in basis 2, I can coumpute it is basis "e" using just
  the relation between the two logarithms
  
  My question is: Is there any good way to compute them using as much
  precision as I need?

I'd suggest that you look at MPFR, see www.mpfr.org.  

-- 
Torbjörn