45. inertia — inertia.py — pyFormex 0.9.1 documentation

### Navigation

- index
- modules |
- next |
- previous |
- pyFormex 0.9.1 documentation >
- pyFormex reference manual >

# 45. `inertia` — inertia.py

Compute inertia related quantities of a Formex. This comprises: center of gravity, inertia tensor, principal axes

Currently, these functions work on arrays of nodes, not on Formices! Use func(F,f) to operate on a Formex F.

`Classes defined in module inertia`

`Functions defined in module inertia`

`inertia.` `centroids`(X)

  Compute the centroids of the points of a set of elements.

  X (nelems,nplex,3)

`inertia.` `center`(X, mass=None)

  Compute the center of gravity of an array of points.

  mass is an optional array of masses to be atributed to the points. The default is to attribute a mass=1 to all points.

  If you also need the inertia tensor, it is more efficient to use the inertia() function.

`inertia.` `inertia`(X, mass=None)

  Compute the inertia tensor of an array of points.

  mass is an optional array of masses to be atributed to the points. The default is to attribute a mass=1 to all points.

  The result is a tuple of two float arrays:

  > - the center of gravity: shape (3,)
  > - the inertia tensor: shape (6,) with the following values (in order): Ixx, Iyy, Izz, Ixy, Ixz, Iyz

`inertia.` `principal`(inertia, sort=False, right_handed=False)

  Returns the principal values and axes of the inertia tensor.

  If sort is True, they are sorted (maximum comes first). If right_handed is True, the axes define a right-handed coordinate system.

### Navigation

- index
- modules |
- next |
- previous |
- pyFormex 0.9.1 documentation >
- pyFormex reference manual >