AMDG On 05/26/2011 09:49 PM, Eric Niebler wrote:

Many accumulators tests are now failing on both trunk and release. I have tracked it down to recent changes in Boost.Random. I don't know for how long this has been happening.

The accumulators tests use the lagged_fibonacci607 random number generator. The tests work by sending a large amount of random data through various statistical accumulators and checking that the results are within a certain tolerance of what they would be if the data were actually random. In Boost 1.45 and previous versions, this worked. (I haven't tested 1.46.) Trunk and release are hosed, leading me to suspect that this random number generator is no longer producing sufficiently random data.

I have verified this by replacing boost/random on trunk with the one from 1.45. With this change, the accumulators tests pass.

Steven, this seems like a regression. Can you look into this?

I think the only thing I changed was the seeding algorithm. The number of random bits was reduced from 53 to 48, but that's all lagged_fibonacci607 ever claimed to provide. Your limits may be too low. I switched extended_p_square.cpp to use mt19937_64 and random_device with generate_canonical<double, 53> and it still failed with both. It's getting a bit late tonight. I'll work through the math tomorrow. In Christ, Steven Watanabe