Finalize ProcrustesResult argument names & default values about procrustes

[FanwangM]

This is a very nice point!

We also have an error() function in

procrustes/procrustes/utils.py

Lines 236 to 275 in ab607f1

	def error(array_a, array_b, array_u, array_v=None):
	r"""
	Return the single- or double- sided Procrustes/norm-squared error.
	The single sided error is defined as
	.. math::
	\text{Tr}\left[\left(\mathbf{AU} - \mathbf{B}\right)^\dagger
	\left(\mathbf{AU} - \mathbf{B}\right)\right]
	The double sided Procrustes error is defined as
	.. math::
	\text{Tr}\left[
	\left(\mathbf{U}_1^\dagger \mathbf{A}\mathbf{U}_2 - \mathbf{B}\right)^\dagger
	\left(\mathbf{U}_1^\dagger \mathbf{A}\mathbf{U}_2 - \mathbf{B}\right)\right]
	Parameters
	----------
	array_a : npdarray
	The 2D array :math:`A` being transformed.
	array_b : npdarray
	The 2D reference array :math:`B`.
	array_u : ndarray
	The 2D array representing the transformation :math:`\mathbf{U}`.
	array_v : ndarray, optional
	The 2D array representing the transformation :math:`\mathbf{V}`. If provided, it will
	compute the double-sided Procrustes error. Otherwise, will compute the single-sided
	Procrustes error.
	Returns
	-------
	error : float
	The squared value of the distance between transformed array and reference.
	"""
	array_e = np.dot(array_a, array_u) if array_v is None \
	else np.dot(np.dot(array_u.T, array_a), array_v)
	array_e -= array_b
	return np.trace(np.dot(array_e.T, array_e))

.

To avoid ambiguity, can we name e_opt as distance? Or we can rename error() function as compute_error().
@FarnazH Thanks.