class_docstr: Help lazily evaluate a matrix exponential.
  
  The idea is to not do more work than we need for high expm precision,
  so we lazily compute matrix powers and store or precompute
  other properties of the matrix.
class_docstr_tok: ["Help","lazily","evaluate","a","matrix","exponential",".","The","idea","is","to","not","do","more","work","than","we","need","for","high","expm","precision",",","so","we","lazily","compute","matrix","powers","and","store","or","precompute","other","properties","of","the","matrix","."]
code: def pade13_scaled(self, s):
      b = (
          64764752532480000.0,
          32382376266240000.0,
          7771770303897600.0,
          1187353796428800.0,
          129060195264000.0,
          10559470521600.0,
          670442572800.0,
          33522128640.0,
          1323241920.0,
          40840800.0,
          960960.0,
          16380.0,
          182.0,
          1.0,
      )
      B = self.A * 2**-s
      B2 = self.A2 * 2 ** (-2 * s)
      B4 = self.A4 * 2 ** (-4 * s)
      B6 = self.A6 * 2 ** (-6 * s)
      U2 = _smart_matrix_product(
          B6,
          b[13] * B6 + b[11] * B4 + b[9] * B2,
          structure=self.structure,
      )
      U = _smart_matrix_product(
          B,
          (U2 + b[7] * B6 + b[5] * B4 + b[3] * B2 + b[1] * self.ident),
          structure=self.structure,
      )
      V2 = _smart_matrix_product(
          B6,
          b[12] * B6 + b[10] * B4 + b[8] * B2,
          structure=self.structure,
      )
      V = V2 + b[6] * B6 + b[4] * B4 + b[2] * B2 + b[0] * self.ident
      return U, V
  
imports: from __future__ import division, print_function, absolute_import
  import math
  import numpy
  import scipy.special
  from scipy.linalg.basic import solve, solve_triangular
  from scipy.sparse.base import isspmatrix
  from scipy.sparse.construct import eye
  from scipy.sparse.linalg import spsolve
  import scipy.sparse
  import scipy.sparse.linalg
  from scipy.sparse.linalg.interface import LinearOperator
label_desc: Use image node_id 19 for calling the _ExpmPadeHelper obj's underlying member method code with example usage: obj.pade13_scaled(s) and returns: U,  V