text: import numpy as np
  
  
  def RSE(pred, true):
      return np.sqrt(np.sum((true-pred)**2)) / np.sqrt(np.sum((true-true.mean())**2))
  
  def CORR(pred, true):
      u = ((true-true.mean(0))*(pred-pred.mean(0))).sum(0)
      d = np.sqrt(((true-true.mean(0))**2*(pred-pred.mean(0))**2).sum(0))
      return (u/d).mean(-1)
  
  def MAE(pred, true):
      return np.mean(np.abs(pred-true))
  
  def MSE(pred, true):
      return np.mean((pred-true)**2)
  
  def RMSE(pred, true):
      return np.sqrt(MSE(pred, true))
  
  def MAPE(pred, true):
      return np.mean(np.abs((pred - true) / true))
  
  def MSPE(pred, true):
      return np.mean(np.square((pred - true) / true))
  
  def metric(pred, true):
      mae = MAE(pred, true)
      mse = MSE(pred, true)
      rmse = RMSE(pred, true)
      mape = MAPE(pred, true)
      mspe = MSPE(pred, true)
  
      return mae,mse,rmse,mape,mspe
  