Re: [Help-gsl] strange behaviour of addition of floats and exponential function

[Peter Johansson]

On 1/26/11 6:15 PM, Chandra Sekhar Mallarapu wrote:
> What about this question?
> gsl_sf_exp(0.0000000000000000000000005731906218817495693050559208091994557794428814131237532386326994000326495726)
>  gives me the value as 
> 1.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000,
>  instead of the actual value. What can I do to get a correct answer for the 
> result of the exponential function?
Taylor expansion. You can approximate exp(x) with 1.0+x. If x is a float 
that evaluates to 1.0 on my computer even if you use double (double 
precision) it evaluates to 1.0 on my computer. As mentioned previously, 
if you want 50 decimals precision you need to look at a different solution.

Thanks,
Peter