Re: specfunc error analysis - generated and propagated errors.

[Brian Gough <bjg at network-theory dot co dot uk>]

Jonathan G. Underwood writes: 
 > It would make for a much cleaner design of the specfun code, and
 > also remove the runtime computational overhead of (most-times often
 > unused) the forward error analysis.

If a foo_e function was eating a lot of time in my application, I
would tweak GSL by declaring it "extern inline". The calculation of
the error estimate would then drop out of the corresponding foo
function (by data flow analysis).  

I think this basically does what you want.  If the function is large,
you might need to increase GCC's limit on inlined function size.

For those concerned with peformance, I commend the approach of
Gottbrath et al, http://arxiv.org/abs/astro-ph/9912202.

-- 
Brian Gough