Dear all,
I have encountered a minor bug in a "displace_atoms" command:
If I use a command similar to "displace_atoms test move -\{x\} \-{y} -${z}" and, for example, the "x" variable is negative, the atoms won't be moved in x direction and there won't be any error messages. I'm using the most recent LAMMPS version (25Sep14). A simple script which shows the bug is attached to this message.
Yours faithfully,
Michal Kanski
displace_atoms_bug.in (516 Bytes)
If you are saying you are wanting the input parser to
evaluates --3.0 (with 2 minus signs) as 3.0, then
you’re expecting too much from the LAMMPS input
parser. You also could not say ${x}+2.0 in an input line.
All the parser does is pass the string to the C function
atof(), which does not do math, e.g. evaluate a formula.
You could use an equal-style variable like
variable x equal “-v_myX”
or
variable x equal “v_myX+2.0”
and then myX could eval to a positive or negative
number and it should work. The variable parser
evaluates a formula, the input parser does not.
Steve