code: def rel_error(true, estimate):
      return ((true - estimate) / true).abs().max()
  
imports: from functools import partial
  import unittest
  import warnings
  import torch
  import torchdiffeq
  from problems import construct_problem, PROBLEMS, DTYPES, DEVICES, METHODS, ADAPTIVE_METHODS, FIXED_METHODS, SCIPY_METHODS
label_desc: Use image node_id 1 for calling a global function with example usage: rel_error(true, estimate) and returns: unknown