我抉择用来做学习笔记了，手机电脑都能够看，还能谋福别人。

课程是吴恩达的机器学习课程。后续还会更新pytorch相关笔记。

Machine Learning definition

Machine Learning: Field of study that gives computers the ability to learn without being explicitly programmed.

——Arthur Samuel（1电脑截图快捷键959）

Well-posed Learning Problem: A computer program is said to learn from experience E with resp公积金ect to some task T and some performance measure P, if its per宫颈癌早期症状formance on T, as measured by p, improves wit笔记本h experience E.

——Tom Mitchell（1998）

一个恰当的学习问题定义如下：计算机程序从阅历E中学习，处理某一任务T，进行某一功用度量P，通过P测定在T上的表现因阅历E而前进。

监督学习

在监督学习中，给出一个数据集，算法的五个特性且每个样本都指出正确答案，运用算法猜测出“正确答案”。

Supe笔记本电脑开机黑屏没反应怎样办rvised Learning: We gave the algorithm a data set，i电脑键盘功用基础知识n which the right answers were given. The task of the algorithm was to just produce more of these right answers.

• Regression: Predict continuous valued output（回归问题：猜测一个连续值输出）
• Classifi工商银行客服电话cation: Discrete valued output（分类问题：猜测离散值输出）

回归问题

已知数据元素学习时间和测验分数，简略拟合出一个一元函数。拟合出公式之后，随意给出一个数据即可猜测出对应的另一个数据，比如已知考75分能够电脑截图快捷键ctrl加什么估测温习的3h左右，已知温习3h能够估测出考75分左右。

离散问题

已知不同的身高体重和性别，图中显着看出因为身高体重不同而划分出的性别差异。之后给定一个身高体重数据便能够估测其性别。

例题：

You’re r电脑unning a com工程造价pany and电脑截图快捷键ctrl加什么 you want to develop learning algorithms to address each of two problems

Problem 1：You have a large inve电脑截图快捷键ctrl加什么ntory of identical items电脑显示屏不亮但是主机已开机. You want to predict how many of these items will sell over the next 3 months

Problem 2：Youd like software to examine individual customer accounts and for e电脑ach account decide if it has been hacked /compromised

答案： Treat problem 1 as a regression problem, problem 2 as a算法工程师 classification problem.

p1算法的五个特性猜测销量，肯定是对前史销量数据进行拟合然后得到一个算法工程师曲线模型而进行猜测，因此是回电脑归问题。

p2检测账号，数据是离散的，安全或许不安全，因此是分类问题。google

无监督学习

在无监督学习中，给出数据集，不进行数据差异。程序主动对输入的数据进行分类或分群，以寻找数据的模型和规则。

In Unsupervised Learning, the data that doesn’t have any labels,or that all has the same labels or really no labels.

• clustering algorithm 聚类

将数据进行聚类，作为一个早年的生物学学生，我第一反应便是聚类在生信中运用及其广泛。生信中的聚类，给定DNA序列，就能够主动划分为不同的物种。下图为一个热图。

例算法是什么题：

Of the following ex电脑黑屏amples, which would you address using an unsupervise电脑截图快捷键ctrl加什么d learning algorithm？

• Given email labeled a电脑蓝屏了怎样办修正s spam/ not spam learn a spam filter

• Given a set of news articles f算法设计与剖析ound on the电脑蓝屏了怎样办修正 web, group them into set of articles about the same s笔记tory

• Given a database of customer data, automatically discover market se狗狗币gments and group customers into different market segments

• Given a dataset of p电脑蓝屏了怎样办修正atie电脑蓝屏了怎样办修正nts diagnosed as either having diabetes or n电脑怎样康复出厂设置ot, learn to classify new patients as having diabetes or not.

答案：

• Given a set of news articles found on the web, group them into set of articles about the same story
• Give龚俊n a database of customer data, automatically discover market segments and group customers into different market segments

1.差异是否是垃圾邮件：监督学习-离散

4.差异患者是否患糖电脑怎样截图尿病：监督学习-离散