class_docstr: Class that defines linalg operation on an array
  
  svd version, where svd is taken on original data array, if
  or when it matters
  
  no spectral cutoff in first version
code: def xxtinvhalf(self):
      return np.dot(self.u, self.sinvdiag)
  
imports: import numpy
  from scipy import linalg
  from statsmodels.tools.decorators import cache_readonly
label_desc: Use image node_id 9 for calling the SvdArray obj's underlying member method code with example usage: obj.xxtinvhalf() and returns: np