I reloaded the older version of Racket on my Windows 7 computer and the radix-2 FFTs run fine there. I also tested both versions on my Macbook Pro (32 bit) and got the same behavior - correct results (plots) on 5.1.2 and bad radix-2 results (plots) on 5.1.900.1. code for the mixed-radix and radix-2. So, it isn't limited to Windows 7 or 64-bit.
Doug On Sun, Oct 9, 2011 at 1:44 PM, Doug Williams <[email protected]>wrote: > I downloaded the latest pre-release version (5.1.900.1) to update the > science collection to use the new plot collection. The good news is that > that went very smoothly. The bad news is that some of my FFT routines seem > to be getting incorrect numeric results - at least the plots are very bad. > But, since all of the other plots seem fine, I don't see why these would be > any different. > > So, I suspect that something has changed that affects the numeric > calculations. It is just the radix-2 FFTs that are having the problem. They > do some low-level bit fiddling to do the in-place butterfly addressing for > the FFTs - using things like unsafe-fxlshift (which just looks unfriendly) - > so, I suspect something there. Are the any recent changes that would affect > these kinds of fixed-point operations? > > I've run the code under a previous version of Racket on a 64-bit Linux > (Scientific Linux 6.0) computer and a 32-bit Windows XP computer and get > correct results. So, I don't think it is simply a 32/64 bit problem - unless > it is limited to 64-bit Windows. > > Sorry that was kind of rambling and non-specific, but I was wondering where > to start looking at the problem or what would help someone else look into > it. > > Doug > > > > On Fri, Oct 7, 2011 at 10:19 PM, Ryan Culpepper <[email protected]> wrote: > >> The release process for v5.2 has begun: the `release' branch was >> created for any work that is left and is now bumped to v5.1.90. You >> can go on using the `master' branch as usual, it is now bumped to >> v5.2.0.1 (to avoid having two different trees with the same version). >> >> If you have any bug-fixes and changes that need to go in the release >> then make sure to specify that in the commit message or mail me the >> commit SHA1s. You can `git checkout release' to try it out directly if >> needed -- but do not try to push commits on it (the server will forbid >> it). >> >> Please make sure that code that you're responsible for is as stable >> as possible, and let me know if there is any new work that should >> not be included in this release. >> >> >> NOW IS THE TIME TO FIX BUGS THAT YOU KNOW ABOUT <<< >> >> The time between the `release' branch creation and the actual >> release is for fixing new errors that prevent proper functioning of >> major components and that show up during the preparation for a >> release. You can also finalize piece of work that is not yet >> complete, but please avoid merging new features. >> >> Note that nightly builds will go on as usual (as v5.2.0.1), and >> pre-release builds will be available shortly at >> >> http://pre.racket-lang.org/release/ >> >> Please tell me if you think that this release is significant enough >> that it should be announced on the users list for wider testing. >> -- >> Ryan Culpepper >> _________________________________________________ >> For list-related administrative tasks: >> http://lists.racket-lang.org/listinfo/dev >> > >
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