Scala -- definition of classes and objects + use of associated objects

1. Classes and objects Scala is a functional object-oriented language. It also supports the idea of object-oriented programming, and also has the concept of class and object. We can still develop object-oriented applications based on Scala. 1.1 related concepts What is object oriented? Object oriented is a programming idea, It is based on p ...

Posted by knsito on Sun, 28 Nov 2021 19:14:00 -0800

Scala -- the use of trait trait

1. Introduction to characteristics 1.1 general Sometimes, we will encounter some specific needs, that is, to strengthen the functions of some classes (or objects) without affecting the current inheritance system. For example, there are monkeys and elephants. They all have names, ages and eating functions, but some monkeys are trained by the c ...

Posted by Trekx on Sun, 28 Nov 2021 17:04:54 -0800

[software engineering practice] Hive research - Blog9

[software engineering practice] Hive research - Blog9 2021SC@SDUSC Research content introduction I am responsible for converting the query block QB into a logical query plan (OP Tree) The following code comes from apaceh-hive-3.1.2-src/ql/src/java/org/apache/hadoop/hive/ql/plan, which is my analysis object code. In the previous Hive research ...

Posted by lilRachie on Sun, 28 Nov 2021 04:10:18 -0800

Classification experiment based on communication data

Learning objectives: 1. Understand and master the logistic regression classification method; 2. Master the effect evaluation of logistic regression model; 3. Master the application scenarios of decision tree classification. Learning content: 1. This experiment is the analysis and prediction of telecom customer churn rate. 2. Analy ...

Posted by LowEndTheory on Sun, 28 Nov 2021 03:36:02 -0800

scala -- operator + bit operation + inverse code, complement code and original code

1. Arithmetic operator 1.1 introduction to operators The symbol used to splice variables or constants is called: operator, and the formula connected by operators is called: expression. We often use it in practical development For example: 10 + 3 is an expression, and the + sign is an operator Note: in Scala, operators are not only operator ...

Posted by Scummy12 on Wed, 24 Nov 2021 12:37:04 -0800

Big data foundation

Big data concept Big Data: refers to a data set that cannot be captured, managed and processed by conventional software tools within a certain time range. It is a massive, high growth rate and diversified information asset that requires a new processing mode to have stronger decision-making power, insight and discovery power and process op ...

Posted by mykg4orce on Tue, 23 Nov 2021 18:58:52 -0800

Hadoop - detailed teaching of Java API operation (upload, download, view, delete and create files) of HDFS file system

If Hadoop has not been configured, you can click the link to see how to configure it Basic technical teaching and practical development teaching of major technologies (under continuous updating ··················&middo ...

Posted by ducey on Sun, 21 Nov 2021 22:15:57 -0800

Running machine learning based on Tensorflow framework on Apache hadoop yarn

The links included in the development and application of machine learning introduce the method and process of running machine learning based on Tensorflow framework on apache hadoop yarn (Introduction to the links involved in development and application of machine learning, and the method and process of running machine learning based on ...

Posted by dan182skater on Sun, 21 Nov 2021 19:55:32 -0800

Actual combat of e-commerce offline warehouse project

Actual combat of e-commerce offline warehouse project (Part 2) E-commerce analysis - core transactions 1, Business requirements Select indicators: order quantity, commodity quantity and payment amount, and analyze these indicators by sales region and commodity type. 2, Business database table structure 1. Relationship between databas ...

Posted by pengu on Sat, 20 Nov 2021 03:23:31 -0800

2021SC@SDUSC Code analysis of HBase project -- compressed coding of HBase

2021SC@SDUSC 1, Brief description Coding + compression can double the disk space of data and save considerable storage costs. At the same time, shrinking can usually improve the system throughput, so that the system can do more work In terms of space saving processing at the storage level, HBase provides two schemes: 1. Key based coding. I ...

Posted by Wolphie on Thu, 18 Nov 2021 19:37:18 -0800