def testbackward():
data = np.array([1, 2])
x = Variable(data)
A = Square()
B = Exp()
a = A(x)
y = B(a)
y.grad = np.array([1, 1])
a.grad = B.backward(y.grad)
x.grad = A.backward(a.grad)
return x.grad
if '__file__' in globals():
import os, sys
sys.path.append(os.path.join(os.path.dirname(__file__), '..'))
import numpy as np
from dezero import Variable
from dezero.functions import Square, Exp
A = Square()
B = Exp()
C = Square()
x = Variable(np.array(0.5))
a = A(x)
b = B(a)
y = C(b)
y.grad = np.array(1.0)
b.grad = C.backward(y.grad)
a.grad = B.backward(b.grad)
x.grad = A.backward(a.grad)
print(x.grad)