#1603: CarpetProlongateTest/test_o9 is failing on several machines --------------------+------------------------------------------------------- Reporter: hinder | Owner: eschnett Type: defect | Status: new Priority: major | Milestone: ET_2014_05 Component: Carpet | Version: development version Keywords: | --------------------+------------------------------------------------------- CarpetProlongateTest/test_o9 is failing on Gordon, Mike and Redshift. On Gordon, the differences are

{{{ carpetprolongatetest::difference.d.asc: substantial differences significant differences on 1 (out of 206) lines maximum absolute difference in column 13 is 1.07288360595703e-06 maximum absolute difference in column 14 is 6.98491930961609e-10 maximum relative difference in column 13 is 1.12625729345722e-12 maximum relative difference in column 14 is 3 (insignificant differences on 19 lines) carpetprolongatetest::difference.x.asc: differences below tolerance on 26 lines carpetprolongatetest::difference.y.asc: differences below tolerance on 26 lines carpetprolongatetest::errornorm..asc: differences below tolerance on 1 lines carpetprolongatetest::scalar.d.asc: differences below tolerance on 13 lines carpetprolongatetest::scalar.x.asc: differences below tolerance on 6 lines carpetprolongatetest::scalar.y.asc: differences below tolerance on 4 lines }}}

and on the other machines the results are similar. test.ccl contains

{{{ TEST test_o7 { ABSTOL 2.0e-11 }

TEST test_o9 { ABSTOL 5.0e-10 }

TEST test_o11 { ABSTOL 3.0e-8 } }}}

Higher order prolongation probably leads to more amplification of roundoff differences, which is why the absolute tolerances listed here increase with prolongation order.

On Redshift, which uses -Ofast with gcc, the maximum absolute differences in columns 13 and 14 are just marginally above the tolerance of 5e-10:

{{{ maximum absolute difference in column 13 is 9.31322574615479e-10 maximum absolute difference in column 14 is 6.98491930961609e-10 maximum relative difference in column 13 is 9.77653900570505e-16 maximum relative difference in column 14 is 3 }}}

However on Gordon and Mike, the column 13 absolute difference is 1e-6, which presumably means the data is large, so the relative tolerance will come into play. The default relative tolerance is 1e-12, and the difference in column 13 is marginally above this.

Gordon:

{{{ maximum absolute difference in column 13 is 1.07288360595703e-06 maximum absolute difference in column 14 is 6.98491930961609e-10 maximum relative difference in column 13 is 1.12625729345722e-12 maximum relative difference in column 14 is 3 }}}

Mike:

{{{ maximum absolute difference in column 13 is 1.07288360595703e-06 maximum absolute difference in column 14 is 6.98491930961609e-10 maximum relative difference in column 13 is 1.12625729345722e-12 maximum relative difference in column 14 is 3 }}}

Should we increase both the relative and absolute tolerances for this test to 1e-11? I believe that would make the test pass on all three machines.