In working with small numbers, I usually look for a solution involving a
log transformation. For instance, when a or b are very small, we can
compute the ratio
a / ( a + b )
more safely by
1 / ( 1 + exp( log(b) - log(a) ) )
Alternative data types are sure to cause issues with portability. It's
On Oct 7, 2010, at 2:28 PM, Richard D. Morey wrote:
> I'm using .Call() to call C code from R under Windows (on an Intel Core 2
> duo). The C code involves some very small numbers, and I think I'm losing
> precision using doubles.
The magnitude of numbers has really nothing to do with precisio
I'm using .Call() to call C code from R under Windows (on an Intel
Core 2 duo). The C code involves some very small numbers, and I think
I'm losing precision using doubles. I thought I might use long doubles
to see if I can get that precision back. I have a few questions:
1. Does this affect
