On Sun, 02 Oct 2011 18:38:00 +0200 [email protected] wrote: > Hello, > > Is there some documentation about the precision of the circular (i.e > trigonometric) fonctions, depending on the (plan9) implementation and > the hardware?
Do you mean precision (number of significant bits) or accuracy (closeness to true value)? For a double the precision is 52 bits, for a float 23. > To my limited knowledge, an OS is integer based, so the floating > point support is mainly "user space" and is, despite IEEE754 and due to > the interaction between hardware, software, and programmer, really > floating, but is there a range given for the association of OS/hardware > telling that say sin(r) or asin(s) is accurate, at worst, at some > epsilon near? It depends on the algorithm used, not on the OS. The C standard leaves accuracy upto the implementation. If you care, you can compare the result of a C function with what bc(1) computes for the same function (by using a suitably large scale).
