Tensorflow签名/ Keras

Question

我在定义的自定义指标中遇到了一些问题，如下所示：

@tf.function
def nossa_metrica(y_true, y_pred):
  truepotventolow = K.cast(K.less_equal(y_true[:,0], 4000), 'int8')
  predpotventolow = K.cast(K.less_equal(y_pred[:,0], 4000), 'int8')
  potventolow = sum(truepotventolow*predpotventolow)
  truepotventomed = K.cast(K.greater(y_true[:,0], 4000) & K.less_equal(y_true[:,0], 8500), 'int8')
  predpotventomed = K.cast(K.greater(y_pred[:,0], 4000) & K.less_equal(y_pred[:,0], 8500), 'int8')
  potventomed = sum(truepotventomed*predpotventomed)
  truepotventohigh = K.cast(K.greater(y_true[:,0], 8500), 'int8')
  predpotventohigh = K.cast(K.greater(y_pred[:,0], 8500), 'int8')
  potventohigh = sum(truepotventohigh*predpotventohigh)
  truedesvpadlow = K.cast(K.less_equal(y_true[:,1], 1150), 'int8')
  preddesvpadlow = K.cast(K.less_equal(y_pred[:,1], 1150), 'int8')
  desvpadlow = sum(truedesvpadlow*preddesvpadlow)
  truedesvpadmed = K.cast(K.greater(y_true[:,1], 1150) & K.less_equal(y_true[:,1], 2300), 'int8')
  preddesvpadmed = K.cast(K.greater(y_pred[:,1], 1150) & K.less_equal(y_pred[:,1], 2300), 'int8')
  desvpadmed = sum(truedesvpadmed*preddesvpadmed)
  truedesvpadhigh = K.cast(K.greater(y_true[:,1], 2300), 'int8')
  preddesvpadhigh = K.cast(K.greater(y_pred[:,1], 2300), 'int8')
  desvpadhigh = sum(truedesvpadhigh*preddesvpadhigh)
  truewlslow = K.cast(K.less_equal(y_true[:,2], 0.075), 'int8')
  predwlslow = K.cast(K.less_equal(y_pred[:,2], 0.075), 'int8')
  wlslow = sum(truewlslow*predwlslow)   
  truewlshigh = K.cast(K.greater(y_true[:,2], 0.075), 'int8')
  predwlshigh = K.cast(K.greater(y_pred[:,2], 0.075), 'int8')
  wlshigh = sum(truewlshigh*predwlshigh)
  return (potventolow+potventomed+potventohigh+desvpadlow+desvpadmed+desvpadhigh+wlslow+wlshigh)/((batch_size+max(1,np.int(0.2*batch_size)))*Yclasses)

在model.compile中，出现以下错误：

OperatorNotAllowedInGraphError: iterating over `tf.Tensor` is not allowed: AutoGraph did not convert this function. Try decorating it directly with @tf.function.

有什么主意我该如何解决？