class_docstr: Nonlinear transform coding model.
code: def alpha(self, value):
      value = tf.convert_to_tensor(value, self.dtype)
  
      def get_logit_alpha():
          a = tf.clip_by_value(value / 4.0, 0.0, 1.0)
          logit_alpha = tf.math.log(a / (1.0 - a))
          return logit_alpha
  
      self._logit_alpha.assign(
          tf.cond(value < 0, lambda: self._logit_alpha, get_logit_alpha)
      )
  
imports: import matplotlib.pyplot
  import numpy
  import tensorflow
  import tensorflow_compression
  import tensorflow_probability
  from toy_sources import compression_model
label_desc: Use image node_id 9 for calling the NTCModel obj's underlying member method code with example usage: obj.alpha(value) and returns: logit_alpha