Articles
android

[Positioning problem] Based on matlab GUI SLAM simulation map construction and positioning [including Matlab source code 1120 period]

1. Introduction SLAM is the abbreviation of Simultaneous localization and mapping, which means "synchronous localization and mapping". It is mainly used to solve the problem of robot positioning and map construction when the robot is moving in an unknown environment. In order to let everyone know more about SLAM, the following will be the application of SLAM The domain, SLAM framework, and SLAM classification (sensor-based SLAM classification) are comprehensively explained. This article is only

... Aaron
schedule 14 min read
android

Android image processing 2: PinchImageView source code analysis

PinchImageView use GestureDetector To handle long-press, click, double-click, and inertial sliding events. onTouchEventHandle events such as two-finger zoom and single-finger movement. There are two matrices, one is the external transformation matrix (mOuterMatrix), which mainly records the results of gesture operations, and the other is the internal transformation matrix (getInnerMatrix(Matrix)), which is based onfitCenterThe initial matrix after zooming and panning in the constant zoom mode. T

... Max
schedule 16 min read
android

Android 12 Beta 2 released

Author/Dave Burke, VP of Engineering A few weeks ago at the Google I / O , we announced the Android 12 first Beta version, brought to show your personality that fits your needs the new the UI , improved performance, and still the privacy and security Put it at the core. Android 12 also brings better tools for developers to create a pleasant experience, whether the user is using a mobile phone, laptop, tablet, wearable device or car. Today we brought the second Beta version of Android 12 for ever

... Isaac
schedule 9 min read
android

02. ECMAScript 6 new features

One.let keyword 1.1 Disadvantages of var Disadvantages of using var keyword to declare variables: 1. The variable declared by var has pre-analysis, which causes logical confusion. It can be used first and declared 2. Var can define the same variable repeatedly, the logic is wrong, the second time should be to modify the variable, not to define 3. Var is used in the for loop condition, causing the pollution of the for loop 4. Variables declared by var have no block-level scope (scope in ES5: glob

... Layla
schedule 32 min read
android

[Smart Car Code review]-Finding the turning point

Series of articles [Smart car Code review] curvature calculation, least squares fitting [Smart car Code review] ramp image and control processing [Smart car Code review] Searching for inflection points [Smart car Code review] Small S Judgment on the road with China and S [Smart Car Code review] Determination of roundabouts and line-up operation Smart car resumption diary [1] Menu index review Smart car resumption diary [2] Common PID, variable structure PID, differential first PID, Fuzzy PID, Ex

... Andrea
schedule 11 min read
coder_life

To go to BAT, you should take a look at the interview experience summary

www.cnblogs.com/balloonwj/p... I left my last company in December last year, and until March of this year, I basically spent the interview. Let me first explain the background: Coordinate in Shanghai, do technical development, the position I interviewed is Linux server development, and the most inclined position is server development chief or technical manager. I was also an interviewer for several companies, because in the next few years I was facing a family and technically reached a bottlenec

... Weston
schedule 18 min read
coder_life

Detailed explanation of Linux netstat command and the meaning of state

Linux: netstat -nalp|grep 1883 #View the connection of port 1883 and observe the TCP status diagram netstat -nalp|grep 1883|wc -l #View the number of client connections on port 1883 ulimit -n 5120000 #Modify the maximum number of files in the current process tail -f *.log #View log content in real time   The TCP three-way handshake process is as follows:         The active connection end sends a SYN packet to the passive connection end;         After

... Faith
schedule 13 min read
coder_life

An article to understand SuperEdge distributed health check (cloud)

Du Yanghao, a senior engineer at Tencent Cloud, is passionate about open source, containers and Kubernetes. At present, he is mainly engaged in mirror warehouse, Kubernetes cluster high availability & backup and restoration, and edge computing related research and development. Preface The SuperEdge distributed health check function consists of edge-health-daemon on the side and edge-health-admission on the cloud: edge-health-daemon: Perform distributed health checks on edge nodes in the same

... Sydney
schedule 19 min read
coder_life

Those things about TCP (Part 2)

coolshell.cn/articles/11... This article is the next one, so if you are not familiar with TCP, please take a look at the previous article " Things about TCP ( Part 1)" ". In the previous article, we introduced the protocol header, state machine, and data of TCP. Something in the retransmission. But TCP has to solve a big problem, which is to dynamically adjust its own packet sending speed in a network according to different situations, small to make its connection more stable, and large to make

... Layla
schedule 27 min read
coder_life

Python3.6 study notes (three)

Object-Oriented Programming Object Oriented Programming Object Oriented Programming, abbreviated as OOP, is a programming idea. OOP regards the object as the basic unit of the program. An object contains data and functions to manipulate the data. Process-oriented programming regards a computer program as a series of command sets, that is, the sequential execution of a set of functions. In order to simplify the program design, process-oriented functions continue to be divided into sub-functions,

... Emmett
schedule 19 min read
dev_tools

Elastic Stack 7.8.0 is released

We are very happy to announce the official release of Elastic Stack version 7.8. Like most Elastic releases, 7.8 introduces a large number of new features for Elasticsearch, Kibana, Logstash, and Beats. It also introduces various new features for the following solutions built on the Elastic Stack: Elastic Enterprise Search, Elastic Observability, and Elastic security. We expect that 7.8 can help customers and users import more data into Elastic, streamline navigation and management, and use spec

... Jameson
schedule 13 min read
dev_tools

Piziheng Embedded: Freescale Kinetis series MCU startup those things (2)-KBOOT form (ROM/Bootloader/Flashloader)

Hello, everyone, I am the ruffian, a serious ruffian who engages in technology. Today , Pi Ziheng introduced to you the KBOOT form of Freescale's Kinetis series of MCUs . Pi Ziheng introduced the KBOOT architecture in the previous article . We know that KBOOT is a complete Bootloader solution. This solution is mainly designed for Kinetis chips. At present, there are at least hundreds of models of Kinetis chips. The forms of existence in the Kinetis chips are not exactly the same. KBOOT mainly h

... Miguel
schedule 11 min read
dev_tools

Get Docker commands in one article

Mirror warehouse operation grammar # Log in to the mirror warehouse docker login [OPTIONS] [SERVER] Copy code OPTIONS description: -u: login user name -p: login password # Sign mirroring warehouse docker logout [OPTIONS] [SERVER] Copy code # Search mirrored in the warehouse docker search [OPTIONS] TERM Copy code OPTIONS description: --automated: Only list images of the automated build type --no-trunc: show the complete mirror description -f <filter condition>: List the mirrors whose numbe

... Max
schedule 19 min read
dev_tools

Use HTML5 fragments to upload super-large file code

Requirement: The project should support large file upload function. After discussion, the file upload size is initially controlled within 500M. Therefore, you need to adjust and configure the file upload part in the project, and limit the size to 501M. first step: Front end modification Since the project uses the BJUI front-end framework, it does not use the file upload control of the framework itself, but uses the jQuery-based Uploadify file upload component. In the jslib project used by the pr

... Levi
schedule 16 min read
dev_tools

CSS pseudo-classes & pseudo-elements

definition Why introduce pseudo-classes, pseudo-elements css The concept of pseudo-classes and pseudo-elements is introduced to format information outside the document tree. In other words, pseudo-classes and pseudo-elements are used to modify parts that are not in the document tree, for example, the first letter in a sentence, or the first element in a list What is a pseudo-class Pseudo-classes are used to add corresponding styles to existing elements when they are in a certain state. This stat

... Patrick
schedule 15 min read
programming

The definitive guide to JavaScript reading notes (7th edition)

Crayon Xiaoxin Quotations: A guy who thinks he is strong enough by himself does not have strong qualifications! The author hopes: Reading classic books and communicating with Daniel, reading can fully understand their own shortcomings! JavaScript authoritative guide reading notes (7th edition) "Rhino Book" has a supreme status in the hearts of engineers. Although there are many books on the market that explain the javaScript language and technology, but this book can be close to ECMAScript and W

... Aubrey
schedule 13 min read
programming

Algorithm commonly used data structure

This is the 6th day that I participated in the Wenwen Challenge. For details of the event, please view: Wenwen Challenge Data structure is the cornerstone of the algorithm. Without a solid foundation of data structure, it is very difficult to learn the algorithm well or even integrate it. A good algorithm often depends on which data structure is used. This article mainly introduces the data structure and some practical skills that are often used in algorithm interviews, and at the same time inte

... Jesse
schedule 22 min read
programming

Mongoose of Node (ten) cooperates with Node routing to realize mailbox registration and login (Post version)

First create a new HTML: (import jq) <!DOCTYPE html > < html lang = "en" > < head > < meta charset = "UTF-8" /> < meta name = "viewport" content = "width=device-width, initial-scale=1.0" /> < meta http-equiv = "X-UA-Compatible " content = "ie=edge" /> < title > Document </ title > < script src = "./jquery.js" > </ script > <style > * { margin : 0 ; padding : 0 ; } div :nth-child ( 3 ) { display : none; } input { display : block; h

... Jason
schedule 10 min read
programming

Build large-scale distributed services (three) SpringBoot multi-environment configuration

1. The main points of this article Develop a system that includes at least a development environment, a test environment, and a formal environment, so that the system can run in different environments to run different configurations, such as database, redis, etc., and then the code above will introduce how to integrate springboot + maven + logback + properties Multi-environment configuration. Complete list of articles in the series springboot and maven multi-environment profile Logback multi-env

... Quinn
schedule 11 min read
programming

Data structure|Dictionary and hash table (the front end calls it an object)

Data structure-study notes integration Data structure-stack (study notes) Data structure-queue (study notes) Data structure-linked list (study notes) Data structure-collection (study notes) Data structure|Dictionary and hash table (the front end calls it an object) Data structure-binary tree and binary search tree Data Structure | Binary Heap Preface In the set (Set), our focus is on each value of the set (Set). The set (Set) stores elements in the form of [value, value], and in the dictionary,

... Benjamin
schedule 49 min read
1 2 3 4 5 6 7 8 9 10