Olá, poderia me ajudar? O código apresenta o seguinte erro:

UnboundLocalError                         Traceback (most recent call last)
Untitled-1.ipynb Cell 37' in <cell line: 4>()
      6     previstos = prever(df['Area'], theta1, theta0)
      7     print(erro_quadratico_medio(previstos, df['Valor']))
----> 8 theta0, theta1 = gradienteDescendente(theta0, theta1, df['Area'], df['Valor'], 0.01)

Untitled-1.ipynb Cell 34' in gradienteDescendente(tetha0, theta1, X, y, alpha)
      1 def gradienteDescendente(tetha0, theta1, X, y, alpha):
      2     dtheta0, dtheta1 = derivada(tetha0, theta1, X, y)
----> 3     theta0 -= alpha * dtheta0
      4     theta1 -= alpha * dtheta1
      6     return theta0, theta1

UnboundLocalError: local variable 'theta0' referenced before assignment