>>>>> "Edwin" == Edwin Woollett <woollett at charter.net> writes:
Ted> On Nov. 20, Ramond Toy wrote:
Ted> ---------------------------------
Ted> Oops. I've uploaded a new version that fixes this.
Ted>
Ted> Unfortunately, it still takes a very long time. My original test used
Ted> the default parameters and it converged very quickly. With your new
Ted> parameters, I gave up after a minute or so.
Ted>
Ted> But I think the problem is with the integrand, 1/(1+sqrt(x)). I'm
Ted> guessing the infinite slope at 0 is going to give lots of trouble.
Ted> bromberg(g, 1/2, 1) returns instantly. bromberg(g,1/100,1) takes a
Ted> little bit longer.
Ted> ----------------------------------------
Ted> The new version of bromberg.lisp,
Ted> http://common-lisp.net/~rtoy/maxima/bromberg.lisp
Ted> no longer gives a lisp error (gcl), but is extremely
Ted> slow (I stopped the calculation after 13 min)
Ted> if I ask for 20 digit precision for the same
[snip]
Edwin> (%i9) brombergabs:1.0b-20;
Edwin> (%o9) 1.0b-20
Edwin> (%i10) bval : bromberg(g,1/2,1);
Edwin> Maxima encountered a Lisp error:
Edwin> Console interrupt.
Edwin> -------------------------------------------
Edwin> I stopped the calculation after 13 min.
What kind of machine are you running this on?
I finally got around to building maxima with gcl on the only machine I
have access to with a working gcl. On that machine (an aging
Ultrasparc, 750 MHz), I get this with your example:
bromberg((1/(1+sqrt(x)),x,1/2,1);
Evaluation took 0.7300 seconds (0.7600 elapsed)
(%o15) 2.6909206998615507341183361093738044447610421970518b-1
So, that's less than one second on this ancient 750 MHz sparc box.
Since you take over 13 minutes, either your machine is a 1 MHz box,
or there's something weird with your version of gcl and/or maxima.
Ray