pyyeti.nastran.n2p.rbgeom

pyyeti.nastran.n2p.rbgeom(grids, refpoint=array([[0, 0, 0]]))

Compute 6 rigid-body modes from geometry.

Parameters:

• grids (3-column matrix) – Coordinates in basic; columns are [x, y, z].

• refpoint (integer or 3-element vector) – Defines location that rb modes will be relative to: either row index into grids (starting at 0) or the [x, y, z] location.

Returns:

rb (ndarray) – Rigid-body modes; rows(grids)*6 x 6.

Notes

All grids are assumed to be in the same rectangular coordinate system. For a much more sophisticated routine, see rbgeom_uset().

Examples

>>> import numpy as np
>>> from pyyeti import nastran
>>> grids = np.array([[0., 0., 0.], [30., 10., 20.]])
>>> nastran.rbgeom(grids)
array([[  1.,   0.,   0.,   0.,   0.,  -0.],
       [  0.,   1.,   0.,  -0.,   0.,   0.],
       [  0.,   0.,   1.,   0.,  -0.,   0.],
       [  0.,   0.,   0.,   1.,   0.,   0.],
       [  0.,   0.,   0.,   0.,   1.,   0.],
       [  0.,   0.,   0.,   0.,   0.,   1.],
       [  1.,   0.,   0.,   0.,  20., -10.],
       [  0.,   1.,   0., -20.,   0.,  30.],
       [  0.,   0.,   1.,  10., -30.,   0.],
       [  0.,   0.,   0.,   1.,   0.,   0.],
       [  0.,   0.,   0.,   0.,   1.,   0.],
       [  0.,   0.,   0.,   0.,   0.,   1.]])