Hi David, On 25/11/2011 16:09, David Coeurjolly wrote: Actually, it seems to be a wrong behavior in Olena, your example is correct. accu::stat::max accumulator is initialized using mln_min(double) in your case. However, it seems that instead of returning the effective negative minimum double value, it returns the minimum positive double value which is not expected. This bug is now referenced here : https://trac.lrde.org/olena/ticket/247 We are running the tests to check if it breaks anything. Thanks for your report. Regards, Guillaume