The question of continuous idenfication and discrete identification

[jackyvava]

When I run code on colab, I always get errors when running the continuous idenfication and discrete identification modules：

None
—— Starting Adam optimization ——

KeyError Traceback (most recent call last)
in <cell line: 40>()
38 layers[-1] = q
39 pinn = PhysicsInformedNN(layers, tf_optimizer, logger, dt, lb, ub, q, IRK_alpha, IRK_beta)
---> 40 pinn.fit(x_0, u_0, x_1, u_1, tf_epochs)
41 U_0_pred, U_1_pred = pinn.predict(x_star)
42 lambda_1_pred_noisy, lambda_2_pred_noisy = pinn.get_params(numpy=True)

13 frames
/usr/local/lib/python3.10/dist-packages/keras/optimizers/optimizer.py in _update_step(self, gradient, variable)
230 return
231 if self._var_key(variable) not in self._index_dict:
--> 232 raise KeyError(
233 f"The optimizer cannot recognize variable {variable.name}. "
234 "This usually means you are trying to call the optimizer to "

KeyError: in user code:

File "/usr/local/lib/python3.10/dist-packages/keras/optimizers/optimizer.py", line 224, in _update_step_xla  *
    return self._update_step(gradient, variable)
File "/usr/local/lib/python3.10/dist-packages/keras/optimizers/optimizer.py", line 232, in _update_step  **
    raise KeyError(

KeyError: 'The optimizer cannot recognize variable dense_4/kernel:0. This usually means you are trying to call the optimizer to update different parts of the model separately. Please call `optimizer.build(variables)` with the full list of trainable variables before the training loop or use legacy optimizer `tf.keras.optimizers.legacy.Adam.'