code: def _get_ip_op_distance_signal(ip_op_dist, bias_val, decay):
      """Signal on distance from input to output."""
      return np.exp(-decay * abs(ip_op_dist - bias_val))
  
file_path: dragonfly/dragonfly/nn/syn_nn_functions.py
imports: import numpy
label_desc: Use image node_id 4 for calling a global function with example usage: _get_ip_op_distance_signal(ip_op_dist, bias_val, decay) and returns: np