# 3d Lennard-Jones melt with equal- and atom-style variables which
#   use a Python function wrapper in their formulas

variable        x index 5
variable        y index 5
variable        z index 5

units           lj
atom_style      atomic

lattice         fcc 0.8442
region          box block 0 $x 0 $y 0 $z
create_box      1 box
create_atoms    1 box
mass            1 1.0

velocity        all create 1.44 87287 loop geom

pair_style      lj/cut 2.5
pair_coeff      1 1 1.0 1.0 2.5

neighbor        0.3 bin
neigh_modify    delay 0 every 20 check no

fix             1 all nve

variable        foo python truncate
python          truncate return v_foo input 1 v_pyarg1 format fi here """
def truncate(x):
  return int(x)
"""
variable        pyarg1 internal 0.0

variable        scalar equal py_foo(4.5)
print           "TRUNCATE ${scalar}"

variable        xtrunc atom py_foo(x)
variable        ytrunc atom py_foo(y)
variable        ztrunc atom py_foo(z)

# examine dump file to see truncated xyz coords of each atom

#dump            1 all custom 100 tmp.dump id x y z
dump            1 all custom 100 tmp.dump id x y z v_xtrunc v_ytrunc v_ztrunc

run             100