(frame, ixx, iyy, izz, ixy=0, iyz=0, izx=0)
return ol
Simple way to create inertia Dyadic object.

    If you don't know what a Dyadic is, just treat this like the inertia
    tensor.  Then, do the easy thing and define it in a body-fixed frame.

    Parameters
    ==========

    frame : ReferenceFrame
        The frame the inertia is defined in
    ixx : Sympifyable
        the xx element in the inertia dyadic
    iyy : Sympifyable
        the yy element in the inertia dyadic
    izz : Sympifyable
        the zz element in the inertia dyadic
    ixy : Sympifyable
        the xy element in the inertia dyadic
    iyz : Sympifyable
        the yz element in the inertia dyadic
    izx : Sympifyable
        the zx element in the inertia dyadic

    Examples
    ========

    >>> from sympy.physics.mechanics import ReferenceFrame, inertia
    >>> N = ReferenceFrame('N')
    >>> inertia(N, 1, 2, 3)
    (N.x|N.x) + 2*(N.y|N.y) + 3*(N.z|N.z)
Simple way to create inertia Dyadic object.
Simple way to create inertia Dyadic object .
def inertia(frame, ixx, iyy, izz, ixy=0, iyz=0, izx=0):
    """Simple way to create inertia Dyadic object.

    If you don't know what a Dyadic is, just treat this like the inertia
    tensor.  Then, do the easy thing and define it in a body-fixed frame.

    Parameters
    ==========

    frame : ReferenceFrame
        The frame the inertia is defined in
    ixx : Sympifyable
        the xx element in the inertia dyadic
    iyy : Sympifyable
        the yy element in the inertia dyadic
    izz : Sympifyable
        the zz element in the inertia dyadic
    ixy : Sympifyable
        the xy element in the inertia dyadic
    iyz : Sympifyable
        the yz element in the inertia dyadic
    izx : Sympifyable
        the zx element in the inertia dyadic

    Examples
    ========

    >>> from sympy.physics.mechanics import ReferenceFrame, inertia
    >>> N = ReferenceFrame('N')
    >>> inertia(N, 1, 2, 3)
    (N.x|N.x) + 2*(N.y|N.y) + 3*(N.z|N.z)

    """

    if not isinstance(frame, ReferenceFrame):
        raise TypeError('Need to define the inertia in a frame')
    ol = sympify(ixx) * (frame.x | frame.x)
    ol += sympify(ixy) * (frame.x | frame.y)
    ol += sympify(izx) * (frame.x | frame.z)
    ol += sympify(ixy) * (frame.y | frame.x)
    ol += sympify(iyy) * (frame.y | frame.y)
    ol += sympify(iyz) * (frame.y | frame.z)
    ol += sympify(izx) * (frame.z | frame.x)
    ol += sympify(iyz) * (frame.z | frame.y)
    ol += sympify(izz) * (frame.z | frame.z)
    return ol
def inertia ( frame , ixx , iyy , izz , ixy = 0 , iyz = 0 , izx = 0 ) : if not isinstance ( frame , ReferenceFrame ) : raise TypeError ( 'Need to define the inertia in a frame' ) ol = sympify ( ixx ) * ( frame . x | frame . x ) ol += sympify ( ixy ) * ( frame . x | frame . y ) ol += sympify ( izx ) * ( frame . x | frame . z ) ol += sympify ( ixy ) * ( frame . y | frame . x ) ol += sympify ( iyy ) * ( frame . y | frame . y ) ol += sympify ( iyz ) * ( frame . y | frame . z ) ol += sympify ( izx ) * ( frame . z | frame . x ) ol += sympify ( iyz ) * ( frame . z | frame . y ) ol += sympify ( izz ) * ( frame . z | frame . z ) return ol