class_docstr: Orthonormal (for weight=1) Chebychev Polynomial on (-1,1)
  
  
  Notes
  -----
  integration requires to stay away from boundary, offsetfactor > 0
  maybe this implies that we cannot use it for densities that are > 0 at
  boundary ???
  
  or maybe there is a mistake close to the boundary, sometimes integration works.
class_docstr_tok: ["Orthonormal","(","for","weight=1",")","Chebychev","Polynomial","on","(","-1,1",")","Notes","--","--","-","integration","requires","to","stay","away","from","boundary",",","offsetfactor",">","0","maybe","this","implies","that","we","can","not","use","it","for","densities","that","are",">","0","at","boundary","?","?","?","or","maybe","there","is","a","mistake","close","to","the","boundary",",","sometimes","integration","works","."]
code: def __call__(self, x):
      if self.order == 0:
          return (
              np.ones_like(x)
              / (1 - x**2) ** (1 / 4.0)
              / np.sqrt(np.pi)
          )
  
      else:
          return (
              self.poly(x)
              / (1 - x**2) ** (1 / 4.0)
              / np.sqrt(np.pi)
              * np.sqrt(2)
          )
  
imports: from scipy import stats, integrate, special
  import numpy
label_desc: Use image node_id 2 for calling the ChebyTPoly obj's underlying member method code with example usage: obj.__call__(x) and returns: unknown, unknown