在这个keras / tensorflow代码中：
h = input ("Enter the initial height of the ball:"); h = int(h)
v = input ("Enter the initial velocity of the ball:"); v = int (v)
t = input ("Enter the time of the ball"); t = int(t)
maxH = h + (-(v ** 2 )) / ( 2 * (-16))
ballT = (h + (v*t) - (16*t*t))
print("The maximum height of the ball is", maxH, "feet.")
print("After",t,"seconds the ball will be at a height of",ballT,"feet.")
import keras.backend as K
y_pred = model.predict(X)
loss = keras.losses.categorical_crossentropy(
K.variable(y_true),
K.variable(y_pred))
print("K.eval(loss):", K.eval(loss))
给你的是什么？我在哪里可以看到这个？