class_docstr: DimensionSystem represents a coherent set of dimensions.
  
  The constructor takes three parameters:
  
  - base dimensions;
  - derived dimensions: these are defined in terms of the base dimensions
    (for example velocity is defined from the division of length by time);
  - dependency of dimensions: how the derived dimensions depend
    on the base dimensions.
  
  Optionally either the ``derived_dims`` or the ``dimensional_dependencies``
  may be omitted.
docstr: Useless method, kept for compatibility with previous versions.
  
  DO NOT USE.
  
  Return the canonical transformation matrix from the canonical to the
  base dimension basis.
  
  It is the inverse of the matrix computed with inv_can_transf_matrix().
docstr_tok: ["Useless","method",",","kept","for","compatibility","with","previous","versions",".","DO","NOT","USE",".","Return","the","canonical","transformation","matrix","from","the","canonical","to","the","base","dimension","basis",".","It","is","the","inverse","of","the","matrix","computed","with","inv_can_transf_matrix","(",")","."]
code: def can_transf_matrix(self):
      """
      Useless method, kept for compatibility with previous versions.
  
      DO NOT USE.
  
      Return the canonical transformation matrix from the canonical to the
      base dimension basis.
  
      It is the inverse of the matrix computed with inv_can_transf_matrix().
      """
  
      # TODO: the inversion will fail if the system is inconsistent, for
      #      example if the matrix is not a square
      return reduce(
          lambda x, y: x.row_join(y),
          [
              self.dim_can_vector(d)
              for d in sorted(self.base_dims, key=str)
          ],
      ).inv()
  
imports: from __future__ import annotations
  import collections
  from functools import reduce
  from sympy.core.basic import Basic
  from sympy.core.containers import Dict, Tuple
  from sympy.core.singleton import S
  from sympy.core.sorting import default_sort_key
  from sympy.core.symbol import Symbol
  from sympy.core.sympify import sympify
  from sympy.matrices.dense import Matrix
  from sympy.functions.elementary.trigonometric import TrigonometricFunction
  from sympy.core.expr import Expr
  from sympy.core.power import Pow
label_desc: Use image node_id 12 for calling the DimensionSystem obj's underlying member method code with example usage: obj.can_transf_matrix() and returns: reduce