标签:plt Tensor torch storage PyTorch import print 基本操作 numpy
一、Tensor操作
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(1)归并操作
函数 | 功能 |
mean/sum/median/mju | 均值/和/中位数/众数 |
nom/dist | 范数/距离 |
std/var | 标准差/方差 |
cumsum/cumprod | 累加/累乘 |
import torch as t
b=t.ones(2,3)
print(b.sum(dim=0,keepdim=True))
print(b.sum(dim=0,keepdim=False))
print(b.sum(dim=1))
a=t.arange(0,6).view(2,3)
print(a)
a=a.cumsum(dim=1)#沿着行累加
print(a)
----------------------在pycharm中的运行结果-----------------------
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(2)比较
函数 | 功能 |
gt/lt/ge/le/eq/ne | 大于/小于/大于等于/小于等于/等于/不等 |
topk | 最大的K的个数 |
sort | 排序 |
max/min | 比较两个tensor的最大最小值 |
import torch as t
a=t.linspace(0,15,6).view(2,3)
print(a)
b=t.linspace(15,0,6).view(2,3)
print(b)
print(a>b)
print(a[a>b])
print(t.max(a))
print(t.max(b,dim=1))
print(t.max(a,b))
print(t.clamp(a,min=10))
-------------------------------------在pycharm中的运行结果-------------------------------------------
(3)线性代数
函数 | 功能 |
trace | 对角线元素之和 |
diag | 对角线元素 |
triu/tril | 矩阵上三角/下三角 |
mm/bmm | 矩阵乘法/batch的矩阵乘法 |
addmm/addbmm/addmv | 矩阵运算 |
t | 转置 |
dot/cross | 内积/外积 |
inverse | 求逆矩阵 |
svd | 奇异值分解 |
import torch as t
a=t.linspace(0,15,6).view(2,3)
b=a.t()
print(b.is_contiguous())
print(b.contiguous())
-------------------------------------在pycharm中的运行结果-------------------------------------------
(4)tensor和numpy
import torch as t
import numpy as np
a=np.ones([2,3],dtype=np.float32)
print(a)
b=t.from_numpy(a)
print(b)
b=t.Tensor(a)
print(b)
a[0,1]=100
print(b)
c=b.numpy
print(c)
-------------------------------------在pycharm中的运行结果-------------------------------------------
(5)
import torch as t
import numpy as np
a=t.ones(3,2)
b=t.zeros(2,3,1)
print(a+b)
print(a.view(1,3,2).expand(2,3,2)+b.expand(2,3,2))
print(a.unsqueeze(0).expand(2,3,2)+b.expand(2,3,2))
e=a.unsqueeze(0).expand(10000000000000,3,2)
print(e)
(6)
a[1]=100
print(b)
c=a[2:]
print(c.storage())
print(c.data_prt())
print(a.data_ptr())
c[0]=-100
print(a)
d=t.Tensor(c.storage())
d[0]=6666
print(b)
print(id(a.storage())==id(b.storage())==id(c.storage())==id(d.storage()))
print(a.storage_offset())
print(c.storage_offset())
print(d.storage_offset())
e=b[::2,::2]
print(id(a.storage())==id(a.storage()))
print(b.stride())
print(e.stride())
print(e.is_contiguous())
(7)
import torch as t
import timeit
a=t.arange(0,6)
print(a.storage())
b=a.view(2,3)
print(b.storage())
print(id(b.storage())==id(a.storage()))
def for_loop_add(x,y):
result = []
for i, j in zip(x, y):
result.append(i + j)
return t.Tensor(result)
a = t.zeros(100)
b = t.ones(100)
t2 = timeit.Timer('a+b')
print(t2)
t1=timeit.Timer('for_loop_add(a,b)')
print(t1)
(8)
import torch as t
a=t.arange(0,2000000)
print(a[-1],a[-2])
b=t.LongTensor()
t.arange(0,20000000,out=b)
print(b[-1])
print(b[-2])
a=t.randn(2,3)
print(a)
t.set_printoptions(precision=10)
print(a)
二、线性回归项目
import torch as t
from matplotlib import pyplot as plt
from IPython import display
#设置随机数种子,保证在不同计算机上运行时下面的输出一致
import os
os.environ["KMP_DUPLICATE_LIB_OK"]="TRUE"
t.manual_seed(1000)
def get_fake_data(batch_size=8):
'''产生随机数据:y=x*2+3,加上了一些噪音'''
x = t.rand(batch_size, 1)*20 #生成size为(batch_size, 1)的二维数组,并元素乘20
y = x * 2 + (1+t.rand(batch_size, 1))*3 #用于生成噪音
return x,y
#来看看产生的x-y分布,输出如图所示
x, y = get_fake_data()
plt.scatter(x.squeeze().numpy(), y.squeeze().numpy())
plt.show()
import torch as t
from matplotlib import pyplot as plt
from IPython import display
import os
os.environ["KMP_DUPLICATE_LIB_OK"]="TRUE"
def get_fake_data(batch_size=8):
x = t.rand(batch_size, 1) * 20
y = x * 2 + (1 + t.rand(batch_size, 1)) * 3
return x, y
w = t.rand(1, 1)
b = t.zeros(1, 1)
lr = 0.001
for ii in range(2000):
x, y = get_fake_data()
y_pred = x.mm(w) + b.expand_as(y)
loss = 0.5 * (y_pred - y) ** 2
loss = loss.sum()
dloss = 1
dy_pred = dloss * (y_pred - y)
dw = x.t().mm(dy_pred)
db = dy_pred.sum()
w.sub_(lr * dw)
b.sub_(lr * db)
if ii % 1000 == 0:
display.clear_output(wait=True)
x = t.arange(0, 20).view(-1, 1).float()
y = x.mm(w) + b.expand_as(x)
plt.plot(x.numpy(), y.numpy())
x2, y2 = get_fake_data(batch_size=20)
plt.scatter(x2.numpy(), y2.numpy()) # true data
plt.xlim(0, 20)
plt.ylim(0, 41)
plt.show()
plt.pause(0.5)
print(w.squeeze()[0], b.squeeze()[0])
标签:plt,Tensor,torch,storage,PyTorch,import,print,基本操作,numpy 来源: https://blog.csdn.net/m0_58197804/article/details/122773525
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