coords.Coords.principal_coordsys#

Coords.principal_coordsys(mass=None)#

Return a CoordSys formed by the principal axes of inertia.

Parameters#

mass: 1-dim float array (points(),), optional: The mass to be attributed to each of the points, in the order of n_points(). If not provided, a mass 1.0 will be attributed to each point.

Returns#

CoordSys object.: Coordinate system aligned along the principal axes of the inertia, for the specified point masses. The origin of the CoordSys is the center of mass of the Coords.

See Also#

central_coordsys(): CoordSys at the center of mass, but axes along global directions

Examples#

>>> from hellotriangle.elements import Tet4
>>> print(Tet4.vertices.principal_coordsys())
CoordSys: trl=[0.25 0.25 0.25]; rot=[[ 0.5774  0.5774  0.5774]
                                     [ 0.3424 -0.8131  0.4708]
                                     [ 0.8165 -0.4082 -0.4082]]