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// rewrap.cmd
// Commands to rewrap torus vertices and edges to get them nicely
// within unit cell. This version does 3D and 2D.
// Moves vertices at most one period at a time, so you may have to
// repeat if things are very bad to start with.
// Uses torus wrap representation and wrap_vertex builtin command.
// Usage: rewrap
// Programmer: Ken Brakke, brakke@susqu.edu, http://www.susqu.edu/brakke
rewrap := {
if space_dimension != 3 then
{ errprintf"rewrap is for space dimension 3; for 2D use rewrap2.cmd.\n";
return;
};
local ucoord, dim, ups, downs;
define ucoord real[space_dimension]; // period-based coordinates
define body attribute old_volume real; // so can adjust volconst
define ups integer[3]; // numeric torus wraps
define downs integer[3];
ups := { 1, 64, 4096 };
downs := { 31, 1984, 126976 };
set body old_volume volume;
foreach vertex vv do
{ ucoord := vv.__x * inverse_periods;
for ( dim := 1; dim <= space_dimension ; dim++ )
{ if ucoord[dim] < 0 then wrap_vertex(vv.id,ups[dim])
else if ucoord[dim] > 1 then wrap_vertex(vv.id,downs[dim]);
};
};
local torvol;
torvol := abs(matrix_determinant(torus_periods));
set body volconst floor((old_volume - volume - volconst)/torvol+.5)*torvol;
}
// End rewrap.cmd
// Usage: rewrap
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