#1599: CarpetInterp/waveinterp_2p tests constant in space initial data ---------------------+------------------------------------------------------ Reporter: rhaas | Owner: eschnett Type: defect | Status: new Priority: minor | Milestone: Component: Carpet | Version: development version Resolution: | Keywords: CarpetInterp ---------------------+------------------------------------------------------

#1599: CarpetInterp/waveinterp_2p tests constant in space initial data ---------------------+------------------------------------------------------ Reporter: rhaas | Owner: eschnett Type: defect | Status: new Priority: minor | Milestone: Component: Carpet | Version: development version Resolution: | Keywords: CarpetInterp ---------------------+------------------------------------------------------

Comment (by rhaas):

As far as I can tell relative error checks are not disabled in test.ccl. It only specifies the number of processes to use for each test. I can add a {{{ RELTOL 1e42 }}} to the test to avoid relative differences.

I agree that testing the 2nd time derivative is important.

Would a non-zero 2nd time derivative and not-constant in space data test more of the code? Testing an interpolator with constant (or very low order data) seems not like the best idea. The prolongation tests eg use operators that are as high order as possible while still allowing exact recovery of the result (ie 3rd order polynomial test function for the 3rd order prolongation operators).

#1599: CarpetInterp/waveinterp_2p tests constant in space initial data ---------------------+------------------------------------------------------ Reporter: rhaas | Owner: eschnett Type: defect | Status: reopened Priority: minor | Milestone: Component: Carpet | Version: development version Resolution: | Keywords: CarpetInterp ---------------------+------------------------------------------------------ Changes (by rhaas):

* status: closed => reopened * resolution: fixed =>

Comment:

Turns out that setting reltol to 1e42 as proposed is not the correct solution. The comparison inside of RunTestUtils.pl is {{{ 1745 my $vreltol = $filereltol * $valmax[$count]; 1746 my $vtol = $fileabstol > $vreltol ? $fileabstol : $vreltol; 1747 if ($absdiff[$count] >= $vtol) { 1748 $rundata->{"$thorn $test $file NFAILSTRONG"}++; 1749 last; 1750 } }}} ie setting reltol to 1e42 sets $vreltol to some very large number and ignores abstol. In order to only use abstol, one has to set reltol to 0. The tests actually had larger absolute error than allowed (eg on bluewaters, though I do seem to get different results than Erik does): {{{ arrays1d[2].x.asc: substantial differences significant differences on 170 (out of 204) lines maximum absolute difference in column 13 is 5.94358425587416e-08 maximum relative difference in column 13 is 63.81875 arrays1d[2].y.asc: substantial differences significant differences on 17 (out of 51) lines maximum absolute difference in column 13 is 5.94358425587416e-08 maximum relative difference in column 13 is 4.17201225740553 }}} So even with an ABSTOL=1e-8 (and RELTOL=0. so that it does not matter) this will fail. Please note that all bluewaters tests pass if I compile with -O3 and -mno-fma -mno-fma4 ie disable non-value safe optimization and fused multiply add instructions (which I'd also claim to be not value safe).

#1599: CarpetInterp/waveinterp_2p tests constant in space initial data ---------------------+------------------------------------------------------ Reporter: rhaas | Owner: eschnett Type: defect | Status: reopened Priority: minor | Milestone: Component: Carpet | Version: development version Resolution: | Keywords: CarpetInterp ---------------------+------------------------------------------------------

Comment (by eschnett):

Apparently Cactus compares the error to the larger of the absolute and the relative tolerance. If so, then decreasing (sic!) the relative tolerance should not be necessary, and we only need to increase the absolute tolerance.

#1599: CarpetInterp/waveinterp_2p tests constant in space initial data ---------------------+------------------------------------------------------ Reporter: rhaas | Owner: eschnett Type: defect | Status: reopened Priority: minor | Milestone: Component: Carpet | Version: development version Resolution: | Keywords: CarpetInterp ---------------------+------------------------------------------------------

Comment (by rhaas):

The tolerances were increase in rev 297, 130, 143 of Exact, IDAxiBrillBH and TwoPunctures.

#1599: CarpetInterp/waveinterp_2p tests constant in space initial data ---------------------+------------------------------------------------------ Reporter: rhaas | Owner: eschnett Type: defect | Status: closed Priority: minor | Milestone: Component: Carpet | Version: development version Resolution: fixed | Keywords: CarpetInterp ---------------------+------------------------------------------------------ Changes (by anonymous):

* status: reopened => closed * resolution: => fixed