Created by: lgone2000

复现代码如下，testdist传入相同变量，testdist1 传入两个不同变量。输出结果相同。 第一个梯度并没有对输入变量累加。 公式推导真实值应该为[6,6]

def testdist():
    #
    #input = [x;y]
    #ab= [x;y] * [x,y] = [x*x, x*y; x*y, y*y]
    #cost = x*x+2*x*y+y*y
    #dcost/dx = 2*x+2*y = 6
    #dcost/dy = 2*x+2*y = 6
    fea_dim = 1
    batch_size = 2
    input = fluid.layers.data(name='input', shape=[1], dtype='float32')
    feature = fluid.layers.reshape(input, shape = [-1, fea_dim], name ='feature')
    ab = fluid.layers.matmul(feature, feature, False, True)
    x = fluid.layers.reduce_sum(ab, dim = 1)
    cost = fluid.layers.reduce_sum(x, dim = 0)
    fetch_list = [ab.name,'feature.tmp_0@GRAD']
    data = np.array([[1],[2]], np.float32) 
    optimizer = fluid.optimizer.SGD(learning_rate=0.0001)
    opts = optimizer.minimize(cost)
    place = fluid.CPUPlace()
    exe = fluid.Executor(place)
    exe.run(fluid.default_startup_program())

    loss = exe.run(
                fluid.default_main_program(),
                feed={'input': data},
                fetch_list=fetch_list
            )
    #print list(fluid.default_main_program().list_vars())
    print '#'*20, loss
def testdist1():
    fea_dim = 1
    batch_size = 2
    input1 = fluid.layers.data(name='input1', shape=[1], dtype='float32')
    input2 = fluid.layers.data(name='input2', shape=[1], dtype='float32')
    feature1 = fluid.layers.reshape(input1, shape = [-1, fea_dim], name = 'feature1')
    feature2 = fluid.layers.reshape(input2, shape = [-1, fea_dim], name = 'feature2')
    
    ab = fluid.layers.matmul(feature1, feature2, False, True)
    x = fluid.layers.reduce_sum(ab, dim = 1)
    cost = fluid.layers.reduce_sum(x, dim = 0)

    fetch_list = [ab.name,'feature1.tmp_0@GRAD', 'feature2.tmp_0@GRAD']
    data = np.array([[1],[2]], np.float32) 
    
    optimizer = fluid.optimizer.SGD(learning_rate=0.0001)
    opts = optimizer.minimize(cost)
    place = fluid.CPUPlace()
    exe = fluid.Executor(place)
    exe.run(fluid.default_startup_program())
    loss = exe.run(
                fluid.default_main_program(),
                feed={'input1': data,'input2':data},
                fetch_list=fetch_list
            )
    print '#'*20, loss