def reconstruct_skel_matrix(A, k, idx):
 if _is_real(A):
  return backend.idd_copycols(A, k, (idx + 1))
 else:
  return backend.idz_copycols(A, k, (idx + 1))

def reconstruct_skel_matrix ( A , k , idx ) : if _is_real ( A ) : return backend . idd_copycols ( A , k , ( idx + 1 ) ) else : return backend . idz_copycols ( A , k , ( idx + 1 ) )
reconstruct skeleton matrix from id .