lightGBM example – feature screening and scorecard model construction

The data still uses the data in this example, and the specific background is the same as above. Add model construction – use logistic regression to build models, lightGBM for feature screening For an introduction to the lightGBM model, please see this link: Integrated Learning – Boosting Algorithm: Brief Principles and Differences of Adaboost, GBDT, […]

In-depth analysis of Java generics: understanding generic principles and practical application methods

Java added a generic mechanism in 1.5, and it is said that experts spent about 5 years on this (sounds rather difficult). With generics, especially the use of collection classes, it becomes more standardized. Take a look at the simple code below. ArrayList<String> list = new ArrayList<String>(); list.add(“Silence King Two”); String str = list. get(0); […]

Write LED driver, create three device files, each device file is bound to a device

head.h #ifndef __HEAD_H__ #define __HEAD_H__ typedef struct{ unsigned int MODER; unsigned int OTYPER; unsigned int OSPEEDR; unsigned int PUPDR; unsigned int IDR; unsigned int ODR; }gpio_t; #define GPIOE 0x50006000 #define GPIOF 0x50007000 #define GPIOB 0x50003000 #define RCC 0X50000A28 #define LED_ON_IOW(‘l’,1,int) #define LED_OFF _IOW(‘l’,0,int) #endif test.c #include <stdlib.h> #include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> […]

Docker installs MySQL cluster (one master and one slave)

Table of Contents Docker installs MySQL cluster (one master and one slave) Appetizer test MySQL cluster installation master container slave container master container Configure master-slave assignment test docker installs MySQL cluster (one master and one slave) Appetizer test 1. Pull the image of mysql5.7 to the local [root@aliyun ~]# docker pull mysql:5.7 2. Start the […]

Postgresql creates partition table index online

postgresql creates partition table index online Partition table online create index error Regarding online index creation, we can add the parameter CONCURRENTLY when creating index But when using this parameter on the partition table, an error will be reported test_db=# create index CONCURRENTLY on test_p_t(num); ERROR: cannot create index on partitioned table “test_p_t” concurrently Problem […]

NLP From Scratch: Classifying Surnames Using char-RNN

NLP From Scratch: Using char-RNN to classify surnames In this post we will build and train a basic character-level RNN to classify words. This tutorial, and the two that follow, show how to preprocess the data “from scratch” for the NLP modeling process, coding without many of the convenience features of torchtext, allowing you to […]

Extended Kalman Filter EKF Formula and Matlab Realization

Introduction to EKF First of all, the function of kalman filter is to make optimal estimation in a dynamic system containing uncertainty, and filtering means estimation. However, the kalman filter can only estimate the linear system. It requires the state transition equation and the observation equation to be linear. Specifically, the following state transition equation […]

MySQL download and installation

MySQL download and installation 1. Download Address: https://dev.mysql.com/downloads/mysql/ The latest version is 8.0, I choose the latest mysql-5.7.24-winx64.zip < img src="//i2.wp.com/img-blog.csdnimg.cn/20181028104229374.?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaX hpbl80Mjg2OTM2NQ==, size_27, color_FFFFFF, t_70"> 2. Installation There are two types of MySQL installation files: .msi and .zip, and .msi needs to be installed The zip format is decompressed by yourself. After decompression, MySQL can […]

node multiple ways to connect to mysql

In Node.js, there are multiple ways to connect to a MySQL database. Here are a few commonly used methods: 1. Use the mysql module: mysql is a popular third-party module that can be installed via npm. You can use the createConnection() method provided by this module to create a database connection and execute SQL queries […]

Unicode, URL encoding, HTML entity symbol encoding

Character encoding Inside a computer, all information is ultimately represented by binary values. Character encoding is the encoding specification for converting natural language into computer language. 1. ASCII code The ASCII code specifies a total of 128 character encodings, including uppercase and lowercase English letters, numbers and some symbols. For example, the space SPACE is […]