这是什么情况?

TypeError                                 Traceback (most recent call last)<ipython-input-24-b78d43ed0331> in <module>()     22 #model.add(Dense(5,input_dim=4))     23 sgd=SGD(lr=0.01,decay=1e-6,momentum=0.9,nesterov=True)---> 24 model.compile(optimizers=sgd,loss="categorical_crossentropy")     25 model.fit(train_data,labels_train,nb_epoch=200,batch_size=40)     26 print(model.predict_classes(test_data))

TypeError: compile() missing 1 required positional argument: 'optimizer'