Project

General

Profile

Bug #884

Don't allow mixed-precision appending

Added by Mark Abraham over 7 years ago. Updated over 7 years ago.

Status:
Closed
Priority:
High
Assignee:
Category:
mdrun
Target version:
Affected version - extra info:
Affected version:
Difficulty:
uncategorized
Close

Description

Apparently you can get mixed precision energy files from appending - see thread http://lists.gromacs.org/pipermail/gmx-users/2012-February/068568.html - which then creates problems later.

I think this should be prevented with an overridable warning.

Also, shouldn't the trajectory and energy file reading routines be able to detect a change of precision and cope gracefully, emitting warnings?

Associated revisions

Revision ecf8f84c (diff)
Added by Berk Hess over 7 years ago

checkpoint files now contain a double precision flag

It was difficult to extract the precision from a checkpoint file.
Now a double precision flag has been added, as well as a fatal error
when mdrun tries to append output files of different precision.
Fixes #884

Change-Id: If333d13639ce80147ee1f6cd0cc34ad1f69afa03

History

#1 Updated by Berk Hess over 7 years ago

We should never allow concatenation when changing precision.
We would like a check in all routines, but this should never happen.

#2 Updated by Rossen Apostolov over 7 years ago

  • Priority changed from Normal to High

#3 Updated by Rossen Apostolov over 7 years ago

  • Target version changed from 4.5.6 to 4.6

Precision is not stored in the file and thus we need a new format. Setting target for 4.6.

#4 Updated by Mark Abraham over 7 years ago

open_enx with do_eheader probes the energy file for precision, so I don't think Rossen's assertion is wholly true, thus I don't think deferral to 4.6 is warranted for that reason. Isn't preventing mixed-precision appending simply a matter of opening the energy file for reading, deducing the precision and comparing it with the run-time precision?

#5 Updated by Berk Hess over 7 years ago

But that would, strictly speaking, require a check for every output file to avoid damaging files.

#6 Updated by Berk Hess over 7 years ago

  • Status changed from New to Closed

I pushed a fix to gerrit for 4.6.

Also available in: Atom PDF