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MindSpore 如何实现一个线性回归 —— Demo示例

如何使用 MindSpore  实现一个简单的  线性回归呢???






根据前面的mindspore的基本操作的学习写出了下面的 一个简单的线性回归算法。


import mindspore
import numpy as np #引入numpy科学计算库
import matplotlib.pyplot as plt #引入绘图库
np.random.seed(123) #随机数生成种子
#from sklearn.model_selection import train_test_split#从sklearn里面引出训练与测试集划分

import mindspore.nn as nn
import mindspore.ops as ops
from mindspore import Tensor
from mindspore import ParameterTuple, Parameter
from mindspore import dtype as mstype


# 训练数据集
def creat_dataset():
n_x=2*np.random.rand(500,1)#随机生成一个0-2之间的,大小为(500,1)的向量
n_y=5+3*n_x+np.random.randn(500,1)#随机生成一个线性方程的,大小为(500,1)的向量
x = Tensor(n_x, dtype=mindspore.float32)
y = Tensor(n_y, dtype=mindspore.float32)
return x, y


class Net(nn.Cell):
def __init__(self, input_dims, output_dims):
super(Net, self).__init__()
self.matmul = ops.MatMul()

self.weight_1 = Parameter(Tensor(np.random.randn(input_dims, 128), dtype=mstype.float32), name='weight_1')
self.bias_1 = Parameter(Tensor(np.zeros(128), dtype=mstype.float32), name='bias_1')
self.weight_2 = Parameter(Tensor(np.random.randn(128, 64), dtype=mstype.float32), name='weight_2')
self.bias_2 = Parameter(Tensor(np.zeros(64), dtype=mstype.float32), name='bias_2')
self.weight_3 = Parameter(Tensor(np.random.randn(64, output_dims), dtype=mstype.float32), name='weight_3')
self.bias_3 = Parameter(Tensor(np.zeros(output_dims), dtype=mstype.float32), name='bias_3')

def construct(self, x):
x = self.matmul(x, self.weight_1)+self.bias_1
x = self.matmul(x, self.weight_2)+self.bias_2
x = self.matmul(x, self.weight_3)+self.bias_3
return x


class LossNet(nn.Cell):
def __init__(self, net):
super(LossNet, self).__init__()
self.net = net
self.pow = ops.Pow()
self.mean = ops.ReduceMean()

def construct(self, x, y):
_x = self.net(x)
loss = self.mean(self.pow(_x - y, 2))
return loss


class GradNetWrtX(nn.Cell):
def __init__(self, net):
super(GradNetWrtX, self).__init__()
self.net = net
self.params = ParameterTuple(net.trainable_params())
self.grad_op = ops.GradOperation(get_by_list=True)

def construct(self, x, y):
gradient_function = self.grad_op(self.net, self.params)
return gradient_function(x, y)


def train(epochs, loss_net, x, y, print_flag=False):
# 构建加和操作
ass_add = ops.AssignAdd()
para_list = loss_net.trainable_params()

for epoch in range(epochs):
grad_net = GradNetWrtX(loss_net)
grad_list = grad_net(x, y)

for para, grad in zip(para_list, grad_list):
ass_add(para, -0.000001*grad)

if print_flag and (epoch%100 == 0):
print("epoch: %s, loss: %s"%(epoch, loss_net(x, y)))


def main():
epochs = 10000
x, y = creat_dataset()

net = Net(x.shape[-1], y.shape[-1])
loss_net = LossNet(net)
train(epochs, loss_net, x, y, False)

y_hat = net(x)

fig=plt.figure(figsize=(8,6))#确定画布大小
plt.title("Dataset")#标题名
plt.xlabel("First feature")#x轴的标题
plt.ylabel("Second feature")#y轴的标题
plt.scatter(x.asnumpy(), y.asnumpy())#设置为散点图
plt.scatter(x.asnumpy(), y_hat.asnumpy())#设置为散点图
plt.show()#绘制出来


if __name__ == '__main__':
""" 设置运行的背景context """
from mindspore import context
# 为mindspore设置运行背景context
context.set_context(mode=context.PYNATIVE_MODE, device_target='GPU')
import time
a = time.time()
main()
b = time.time()
print(b-a)



最终结果:

MindSpore   如何实现一个线性回归  ——   Demo示例_随机数生成




多次运行后,平均运行时间:

 41秒


 

MindSpore   如何实现一个线性回归  ——   Demo示例_python_02





运行环境:

Ubuntu18.04系统

i7-9700HQ

笔记本显卡 1660ti



 ======================================================================================




发现一个神奇的事情,如果我们把context的模式设置为  GRAPH_MODE

也就是:

context.set_context(mode=context.GRAPH_MODE, device_target='GPU')



那么运行过程中会不停的提示警告:


[WARNING] OPTIMIZER(4150,python):2021-07-06-23:07:07.536.303 [mindspore/ccsrc/frontend/optimizer/ad/dfunctor.cc:860] FindPrimalJPair] J operation has no relevant primal call in the same graph. Func graph: 1116905_construct_wrapper, J user: 1116905_construct_wrapper:construct{[0]: 7496, [1]: x, [2]: y, [3]: ValueNode<UMonad> U}
[WARNING] OPTIMIZER(4150,python):2021-07-06-23:07:07.664.157 [mindspore/ccsrc/frontend/optimizer/ad/dfunctor.cc:860] FindPrimalJPair] J operation has no relevant primal call in the same graph. Func graph: 1117054_construct_wrapper, J user: 1117054_construct_wrapper:construct{[0]: 7497, [1]: x, [2]: y, [3]: ValueNode<UMonad> U}
[WARNING] OPTIMIZER(4150,python):2021-07-06-23:07:07.787.667 [mindspore/ccsrc/frontend/optimizer/ad/dfunctor.cc:860] FindPrimalJPair] J operation has no relevant primal call in the same graph. Func graph: 1117203_construct_wrapper, J user: 1117203_construct_wrapper:construct{[0]: 7498, [1]: x, [2]: y, [3]: ValueNode<UMonad> U}
[WARNING] OPTIMIZER(4150,python):2021-07-06-23:07:07.906.649 [mindspore/ccsrc/frontend/optimizer/ad/dfunctor.cc:860] FindPrimalJPair] J operation has no relevant primal call in the same graph. Func graph: 1117352_construct_wrapper, J user: 1117352_construct_wrapper:construct{[0]: 7499, [1]: x, [2]: y, [3]: ValueNode<UMonad> U}
[WARNING] OPTIMIZER(4150,python):2021-07-06-23:07:08.021.086 [mindspore/ccsrc/frontend/optimizer/ad/dfunctor.cc:860] FindPrimalJPair] J operation has no relevant primal call in the same graph. Func graph: 1117501_construct_wrapper, J user: 1117501_construct_wrapper:construct{[0]: 7500, [1]: x, [2]: y, [3]: ValueNode<UMonad> U}
[WARNING] OPTIMIZER(4150,python):2021-07-06-23:07:08.136.975 [mindspore/ccsrc/frontend/optimizer/ad/dfunctor.cc:860] FindPrimalJPair] J operation has no relevant primal call in the same graph. Func graph: 1117650_construct_wrapper, J user: 1117650_construct_wrapper:construct{[0]: 7501, [1]: x, [2]: y, [3]: ValueNode<UMonad> U}
[WARNING] OPTIMIZER(4150,python):2021-07-06-23:07:08.271.804 [mindspore/ccsrc/frontend/optimizer/ad/dfunctor.cc:860] FindPrimalJPair] J operation has no relevant primal call in the same graph. Func graph: 1117799_construct_wrapper, J user: 1117799_construct_wrapper:construct{[0]: 7502, [1]: x, [2]: y, [3]: ValueNode<UMonad> U}
[WARNING] OPTIMIZER(4150,python):2021-07-06-23:07:08.380.832 [mindspore/ccsrc/frontend/optimizer/ad/dfunctor.cc:860] FindPrimalJPair] J operation has no relevant primal call in the same graph. Func graph: 1117948_construct_wrapper, J user: 1117948_construct_wrapper:construct{[0]: 7503, [1]: x, [2]: y, [3]: ValueNode<UMonad> U}
[WARNING] OPTIMIZER(4150,python):2021-07-06-23:07:08.489.950 [mindspore/ccsrc/frontend/optimizer/ad/dfunctor.cc:860] FindPrimalJPair] J operation has no relevant primal call in the same graph. Func graph: 1118097_construct_wrapper, J user: 1118097_construct_wrapper:construct{[0]: 7504, [1]: x, [2]: y, [3]: ValueNode<UMonad> U}
[WARNING] OPTIMIZER(4150,python):2021-07-06-23:07:08.599.613 [mindspore/ccsrc/frontend/optimizer/ad/dfunctor.cc:860] FindPrimalJPair] J operation has no relevant primal call in the same graph. Func graph: 1118246_construct_wrapper, J user: 1118246_construct_wrapper:construct{[0]: 7505, [1]: x, [2]: y, [3]: ValueNode<UMonad> U}
[WARNING] OPTIMIZER(4150,python):2021-07-06-23:07:08.707.115 [mindspore/ccsrc/frontend/optimizer/ad/dfunctor.cc:860] FindPrimalJPair] J operation has no relevant primal call in the same graph. Func graph: 1118395_construct_wrapper, J user: 1118395_construct_wrapper:construct{[0]: 7506, [1]: x, [2]: y, [3]: ValueNode<UMonad> U}
[WARNING] OPTIMIZER(4150,python):2021-07-06-23:07:08.812.025 [mindspore/ccsrc/frontend/optimizer/ad/dfunctor.cc:860] FindPrimalJPair] J operation has no relevant primal call in the same graph. Func graph: 1118544_construct_wrapper, J user: 1118544_construct_wrapper:construct{[0]: 7507, [1]: x, [2]: y, [3]: ValueNode<UMonad> U}





MindSpore   如何实现一个线性回归  ——   Demo示例_随机数生成_03




具体代码:

MindSpore   如何实现一个线性回归  ——   Demo示例_随机数生成_04MindSpore   如何实现一个线性回归  ——   Demo示例_MindSpore(深度学习计算框架)_05

import mindspore
import numpy as np #引入numpy科学计算库
import matplotlib.pyplot as plt #引入绘图库
np.random.seed(123) #随机数生成种子
#from sklearn.model_selection import train_test_split#从sklearn里面引出训练与测试集划分

import mindspore.nn as nn
import mindspore.ops as ops
from mindspore import Tensor
from mindspore import ParameterTuple, Parameter
from mindspore import dtype as mstype


# 训练数据集
def creat_dataset():
n_x=2*np.random.rand(500,1)#随机生成一个0-2之间的,大小为(500,1)的向量
n_y=5+3*n_x+np.random.randn(500,1)#随机生成一个线性方程的,大小为(500,1)的向量
x = Tensor(n_x, dtype=mindspore.float32)
y = Tensor(n_y, dtype=mindspore.float32)
return x, y


class Net(nn.Cell):
def __init__(self, input_dims, output_dims):
super(Net, self).__init__()
self.matmul = ops.MatMul()

self.weight_1 = Parameter(Tensor(np.random.randn(input_dims, 128), dtype=mstype.float32), name='weight_1')
self.bias_1 = Parameter(Tensor(np.zeros(128), dtype=mstype.float32), name='bias_1')
self.weight_2 = Parameter(Tensor(np.random.randn(128, 64), dtype=mstype.float32), name='weight_2')
self.bias_2 = Parameter(Tensor(np.zeros(64), dtype=mstype.float32), name='bias_2')
self.weight_3 = Parameter(Tensor(np.random.randn(64, output_dims), dtype=mstype.float32), name='weight_3')
self.bias_3 = Parameter(Tensor(np.zeros(output_dims), dtype=mstype.float32), name='bias_3')

def construct(self, x):
x = self.matmul(x, self.weight_1)+self.bias_1
x = self.matmul(x, self.weight_2)+self.bias_2
x = self.matmul(x, self.weight_3)+self.bias_3
return x


class LossNet(nn.Cell):
def __init__(self, net):
super(LossNet, self).__init__()
self.net = net
self.pow = ops.Pow()
self.mean = ops.ReduceMean()

def construct(self, x, y):
_x = self.net(x)
loss = self.mean(self.pow(_x - y, 2))
return loss


class GradNetWrtX(nn.Cell):
def __init__(self, net):
super(GradNetWrtX, self).__init__()
self.net = net
self.params = ParameterTuple(net.trainable_params())
self.grad_op = ops.GradOperation(get_by_list=True)

def construct(self, x, y):
gradient_function = self.grad_op(self.net, self.params)
return gradient_function(x, y)


def train(epochs, loss_net, x, y, print_flag=False):
# 构建加和操作
ass_add = ops.AssignAdd()
para_list = loss_net.trainable_params()

for epoch in range(epochs):
grad_net = GradNetWrtX(loss_net)
grad_list = grad_net(x, y)

for para, grad in zip(para_list, grad_list):
ass_add(para, -0.000001*grad)

if print_flag and (epoch%100 == 0):
print("epoch: %s, loss: %s"%(epoch, loss_net(x, y)))


def main():
epochs = 10000
x, y = creat_dataset()

net = Net(x.shape[-1], y.shape[-1])
loss_net = LossNet(net)
train(epochs, loss_net, x, y, False)

y_hat = net(x)

fig=plt.figure(figsize=(8,6))#确定画布大小
plt.title("Dataset")#标题名
plt.xlabel("First feature")#x轴的标题
plt.ylabel("Second feature")#y轴的标题
plt.scatter(x.asnumpy(), y.asnumpy())#设置为散点图
plt.scatter(x.asnumpy(), y_hat.asnumpy())#设置为散点图
plt.show()#绘制出来


if __name__ == '__main__':
""" 设置运行的背景context """
from mindspore import context
# 为mindspore设置运行背景context
#context.set_context(mode=context.PYNATIVE_MODE, device_target='GPU')
context.set_context(mode=context.GRAPH_MODE, device_target='GPU')

import time
a = time.time()
main()
b = time.time()
print(b-a)

View Code


最终结果:

MindSpore   如何实现一个线性回归  ——   Demo示例_MindSpore(深度学习计算框架)_06



============================================================




可以看到不同 context 模式的设置,运行时间相差20倍左右。


# 为mindspore设置运行背景context
context.set_context(mode=context.GRAPH_MODE, device_target='GPU')
context.set_context(mode=context.PYNATIVE_MODE, device_target='GPU')
具体原因是什么,这里也是搞不太清楚???

本文作为尝试使用mindspore功能,具体原因也就不深究了。


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