On 07/27/2012 04:21 AM, Ian Hinder wrote:
Hi Yosef,
I believe the code was reorganised in carpet and this needed the algorithm to change in a way that meant numerical results would change. I can't check right now, but this should have been mentioned in the announcement of the new version of carpet as well as the ET release notes.
Thanks. I was surprised that effect of this change was measurable in the phase at merger (it was of order the differences in phase when I increased the resolution by a factor of 1.2).
-- Ian Hinder ian.hinder@aei.mpg.de mailto:ian.hinder@aei.mpg.de
----- Original message -----
While trying to understand why the results from a BBH run differed when using the 2011_05 and 2011_10 version of ET I noticed that the two versions gave different results on every other point of the buffer region (in a 2 level run) on the 2nd time level.
I reran the test using McLachlan and I found a similar behavior, but for fewer points (here, only 3, rather than 8) and only the innermost points.
diff -w -u ~/ET/Old/Cactus/test/mc/gxx.x.asc ~/ET/Develop/Cactus/test/mc | grep "^[+-]2" -2 0 0 0 0 26 8 8 0.1 1.8 0 0 5.86163790879802 +2 0 0 0 0 26 8 8 0.1 1.8 0 0 5.86163790879801 -2 0 1 0 0 26 8 8 0.1 1.8 0 0 5.86163790879802 +2 0 1 0 0 26 8 8 0.1 1.8 0 0 5.86163790879801 -2 0 1 0 0 59 8 8 0.1 5.1 0 0 2.06954055131151 +2 0 1 0 0 59 8 8 0.1 5.1 0 0 2.06940807802512 -2 0 1 0 0 61 8 8 0.1 5.3 0 0 2.01672019300839 +2 0 1 0 0 61 8 8 0.1 5.3 0 0 2.01674238678588 -2 0 1 0 0 63 8 8 0.1 5.5 0 0 1.96875965038995 +2 0 1 0 0 63 8 8 0.1 5.5 0 0 1.96875664800624