https://www.paddlepaddle.org.cn/documentation/docs/zh/beginners_guide/basic_concept/programming_guide/programming_guide.html

使用上面网址里的编程指南里的demo示例，运行出错，请求专家指导。

运行环境：Python3.7，Windows10：

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Error Message Summary:
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InvalidArgumentError: The Tensor in the elementwise_add Op's Input Variable X(a) is not initialized.
[Hint: Expected t->IsInitialized() == true, but received t->IsInitialized():0 != true:1.] at (D:\1.8.2\paddle\paddle\fluid\framework\operator.cc:1289)
[operator < elementwise_add > error]

-￥￥￥￥-----以下为官方demo小程序-------￥￥￥￥￥￥--------

# 加载库
import paddle.fluid as fluid
import numpy

# 定义输入数据
train_data=numpy.array([[1.0],[2.0],[3.0],[4.0]]).astype('float32')
y_true = numpy.array([[2.0],[4.0],[6.0],[8.0]]).astype('float32')

# 组建网络
x = fluid.data(name="x",shape=[None, 1],dtype='float32')
y = fluid.data(name="y",shape=[None, 1],dtype='float32')
y_predict = fluid.layers.fc(input=x,size=1,act=None)

# 定义损失函数
cost = fluid.layers.square_error_cost(input=y_predict,label=y)
avg_cost = fluid.layers.mean(cost)

# 选择优化方法
sgd_optimizer = fluid.optimizer.SGD(learning_rate=0.01)
sgd_optimizer.minimize(avg_cost)

# 网络参数初始化
cpu = fluid.CPUPlace()
exe = fluid.Executor(cpu)
exe.run(fluid.default_startup_program())

# 开始训练，迭代100次
for i in range(100):
    outs = exe.run(fluid.default_main_program(),
                   feed={'x':train_data, 'y':y_true},
                   fetch_list=[y_predict, avg_cost])

# 输出训练结果
print (outs)