class_docstr: A reference frame in classical mechanics.
  
  ReferenceFrame is a class used to represent a reference frame in classical
  mechanics. It has a standard basis of three unit vectors in the frame's
  x, y, and z directions.
  
  It also can have a rotation relative to a parent frame; this rotation is
  defined by a direction cosine matrix relating this frame's basis vectors to
  the parent frame's basis vectors.  It can also have an angular velocity
  vector, defined in another frame.
docstr: Angular velocity from time differentiating the DCM. 
docstr_tok: ["Angular","velocity","from","time","differentiating","the","DCM","."]
code: def _w_diff_dcm(self, otherframe):
      """Angular velocity from time differentiating the DCM."""
      from sympy.physics.vector.functions import dynamicsymbols
  
      dcm2diff = otherframe.dcm(self)
      diffed = dcm2diff.diff(dynamicsymbols._t)
      angvelmat = diffed * dcm2diff.T
      w1 = trigsimp(expand(angvelmat[7]), recursive=True)
      w2 = trigsimp(expand(angvelmat[2]), recursive=True)
      w3 = trigsimp(expand(angvelmat[3]), recursive=True)
      return Vector([(Matrix([w1, w2, w3]), otherframe)])
  
imports: from sympy import diff, expand, sin, cos, sympify, eye, zeros, ImmutableMatrix, MatrixBase
  from sympy.core.symbol import Symbol
  from sympy.simplify.trigsimp import trigsimp
  from sympy.physics.vector.vector import Vector, _check_vector
  from sympy.utilities.misc import translate
  from warnings import warn
label_desc: Use image node_id 6 for calling the ReferenceFrame obj's underlying member method code with example usage: obj._w_diff_dcm(otherframe) and returns: Vector