class_docstr: A sympy.Symbol type to represent a term an a regression model
  
  Terms can be added to other sympy expressions with the single
  convention that a term plus itself returns itself.
  
  It is meant to emulate something on the right hand side of a formula
  in R. In particular, its name can be the name of a field in a
  recarray used to create a design matrix.
  
  >>> t = Term('x')
  >>> xval = np.array([(3,),(4,),(5,)], np.dtype([('x', np.float64)]))
  >>> f = t.formula
  >>> d = f.design(xval)
  >>> print(d.dtype.descr)
  [('x', '<f8')]
  >>> f.design(xval, return_float=True)
  array([ 3.,  4.,  5.])
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code: def _getformula(self):
      return Formula([self])
  
imports: import itertools
  import warnings
  from string import ascii_letters, digits
  import numpy
  import sympy
  from scipy.linalg import pinv
  from sympy import Dummy, default_sort_key
  from sympy.utilities.lambdify import implemented_function, lambdify
  from nipy.algorithms.utils.matrices import full_rank, matrix_rank
  from nipy.utils import VisibleDeprecationWarning, _NoValue
label_desc: Use image node_id 1 for calling the Term obj's underlying member method code with example usage: obj._getformula() and returns: Formula