[gmx-developers] Bug in analysis programs with frame skipping.

[ramon at juguete.quim.ucm.es]

This is to report that affects all analysis programs when the options -dt
is used. This has been noticed with g_angle.

When a double precision version of these programs is used, 
and a single precision file is analyzed, randoms frame are skipped.

The problem comes from the function bRmod, that checks whether the timestep
is a multiple of the user suplied dt. This function has a tolerance that
depends on the current precision of the build, instead of the precision of
the source file.

The solution would be to add an additional parameter to bRmod, indicating
the precision of the data. As a temporary solution, I suggest using the 
tolerance of single precission.

In addition, it would be great to have a bug tracking system like bugzilla, 
so that these problems are not forgotten. 

Ramon