50 posts
I previously used Alibaba Cloud OSS for personal image hosting, but as the number of posts and images grew and site traffic increased, image-hosting bandwidth also rose and costs kept climbing. So I looked for another platform and found that Cloudflare R2 can provide 10 GB of storage and 10 million free read requests per month.
A project needed a small feature for recognizing text and numbers in images, so I found EasyOCR, a useful open-source library. This article explains how to use it.
When running certain algorithms, you may sometimes need to check system resource usage to see whether the algorithm needs optimization or whether multithreading can be enabled. This requires checking the available system resources.
Environment setup can be tedious, and many programs' dependency environments can conflict with the local environment. Docker is a good way to avoid these issues.
ROS is essential for robot software development, while Qt is essential for graphical user interfaces. This article explains how to use ROS libraries in Qt.
Introduces modal and non-modal dialogs in Qt, as well as standard dialogs.
Introduces how to implement QMainWindow features, including the menu bar, toolbar, status bar, dock widgets, central widget, and more.
Covers Qt basics and walks through creating your first Qt program (an empty window with a button). Introduces signals and slots, and implements the simplest case—closing the window when a button is pressed.
Signals and slots are among the most important concepts in Qt. They enable signal transmission between senders and receivers and form the basis of various Qt operations.
Explains concepts such as O(n) in time complexity and how to calculate time complexity.
Notes from configuring Ubuntu after installation. I recently set up dual-boot systems and also tinkered with a Raspberry Pi; here is a summary.
Python has a rich set of useful built-in modules and third-party modules that make it quick and convenient to implement many common features.
This article summarizes basic Python file reading and writing operations, as well as common os operations on directories and files, such as retrieving paths, joining paths, renaming files, and moving files. It also summarizes commonly used JSON operations.
During program execution, you inevitably encounter all kinds of errors. Some are caused by bugs in the code, some by user input, and others are completely unpredictable at runtime. Python includes a built-in exception-handling mechanism to help us handle errors.
Summarizes basic class usage; the characteristics and application examples of encapsulation, inheritance, and polymorphism; and inheritance-oriented advanced features such as multiple inheritance and customized classes.
In Python, less code is better, and simpler code is better. Based on this philosophy, Python provides many useful advanced features, such as list comprehensions, generators, anonymous functions, and decorators.
Notes and examples on functions and methods for array operations with NumPy, including array creation, slicing and indexing, basic array operations (transposing, joining, sorting, flattening, and more), and the use of some basic array computation functions.
We may want to install many different versions of Python on a computer, or we may want a Python environment to contain only the packages we use so it is easier to package and distribute a program. These situations all require creating Python virtual environments. Anaconda is a tool for managing Python environments like this.
I now publish blog posts on CSDN and my own website at the same time. However, I used to write and publish directly in the CSDN editor, which was an uncomfortable way to work. I still prefer a local Markdown editor such as Typora. This means I need my own image host, so screenshots pasted into the local Markdown editor are automatically uploaded to it.
The lab recently needed to process many spreadsheets, so I built a Python tool to help. The program uses PyQt5 for the graphical interface. This post records the full workflow—from installing PyQt5, to designing the UI, to writing code that drives the widgets, and finally packaging the app as an exe.
CMake is a cross-platform, open-source meta-build system that can build, test, and package software. It can support multiple native build environments. More and more projects are using CMake as their build tool, making CMake a mainstream build system.
Most examples online show a Fork me on GitHub ribbon, but the principle for implementing Follow me on CSDN is the same. Just download and edit the image for the effect you want, upload it to an image host (or CSDN), obtain the image URL, and replace the URL in the code.
Since the NexT theme has been updated several times, many resources said to modify the custom.styl configuration file. However, my theme did not contain this file. After consulting a great deal of material, I finally found the location of the sidebar configuration file.
In Hexo, there are generally two _config.yml files—one in the root directory, which I call the site configuration file, and one in the theme directory, which I call the theme configuration file. This article covers settings such as theme switching, menu configuration, sidebar configuration, author avatar, social links, site name, author name, Chinese/English switching, number of posts shown on the homepage, and translation settings.
First, create the Categories and Tags pages as described below. Then, create a .md file in the source\_posts directory to create a new blog post. Add the following code at the beginning of the post to assign categories and tags; the annotations explain the purpose of each section.
An element can move freely within a box and overlap other boxes. When the window is scrolled, some modules stay fixed at a certain position on the screen. Neither of these effects can be achieved quickly with standard flow or floats alone; positioning is needed in those cases.
Emmet was formerly known as Zen Coding. It uses abbreviations to speed up HTML/CSS coding, and VS Code has built-in support for it.
CSS provides three traditional layout methods—normal flow (standard flow), floats, and positioning. All three are used to arrange boxes. Once the boxes are placed in the appropriate positions, the layout naturally takes shape. In actual development, a page generally includes all three layout methods (mobile devices have newer layout methods).
Web page layout learning has three core topics—the box model, floats, and positioning. Learning the box model helps us lay out pages well. The web page layout process: first prepare the related page elements, use CSS to set the box styles, then place them in the corresponding positions, and put content into the boxes.
CSS classifies selectors by type as basic selectors and composite selectors. Composite selectors are built by combining basic selectors. CSS background properties can add background styles to elements on a page, including background colors, images, tiling, image positions, and fixed background images.
CSS is mainly used to beautify web pages and lay them out. Web pages look unattractive when only HTML is used. CSS is also a markup language, mainly used to set the text content (font, size, alignment, etc.), the appearance of images (width and height, border styles, margins, etc.), and the layout and visual styles of HTML pages.
HTML is a language used to describe web pages. HTML stands for HyperText Markup Language. HTML is not a programming language; it is a markup language. How to use HTML headings, paragraphs, links, and images. Elements, attributes, and formatting; links, styles, and tables; how to create lists, blocks, layouts, and forms.
Data generated while a program is running is temporary and is released once the program finishes. Files can be used to persist data. File operations in C++ require an #include directive.
Inheritance is one of the three core features of object-oriented programming. When defining a class, a lower-level class shares the common characteristics of the level above while also having its own characteristics.
Operator overloading redefines existing operators to give them another function, allowing them to work with different data types. This article covers overloading the addition, left-shift, increment, assignment, relational, and function-call operators.
Some private members may need to be accessed by certain functions or classes outside the class, which requires friends. The keyword for friends is fiend. Friends can be implemented in three ways: a global function as a friend, a class as a friend, or a member function as a friend.
In C++, a class's member variables and member functions are stored separately, and only non-static member variables belong to objects of the class. Each non-static member function has only one function instance, meaning that multiple objects of the same type share one block of code. How does the code distinguish which object invoked it? This is where the this pointer comes in.
Every object needs initial setup and cleanup before it is destroyed. Object initialization and cleanup are two very important safety concerns. Using an object or variable without an initial state has unknown consequences; failing to clean up an object or variable in time after use can also cause safety issues.
Encapsulation combines attributes and behaviors into a whole to represent real-world entities, while controlling access to those attributes and behaviors. When designing a class, attributes and behaviors are written together to represent an entity. The syntax is as follows.
In C++, parameters in a function's parameter list can have default values. If an argument is passed to a parameter, the supplied value is used; otherwise, the default value is used. However, if a parameter at a given position has a default argument, every parameter after it must also have a default value.
I tried using PicGo on Ubuntu, but every time I installed a plugin, it prompted me to install Node.js. Following the installation steps did not solve the issue, so I reinstalled Node.js.
I wanted to connect to my Raspberry Pi remotely using VNC. I searched online and tried many related blog posts and various methods, but I kept running into problems. Finally, after much effort, I found a method that works.
A collection of issues encountered while using Ubuntu.
Building a website requires a server and a domain name. This article covers the entire process of purchasing a server, registering a domain name, configuring the server, installing WordPress, and successfully setting up a blog, as a reference.
First, prepare by installing the Elementor plugin, a theme, and supporting plugins; then import a template and visually edit the site with Elementor; finally, update the site navigation in the WordPress admin dashboard.
In WordPress, content is mainly divided into two parts, posts and pages. WordPress plugins can add, modify, or remove functionality from a WordPress site. The Media Library is mainly used to manage attachments uploaded through WordPress, such as images, videos, and other files.
For the 413 Request Entity Too Large issue, nginx limits the upload size. The solution is as follows: 1. Open the nginx configuration file nginx.conf, usually located at: /etc/nginx/nginx.conf. 2. Add client_max_body_size 64m; to the http{} section. 64m is the maximum allowed upload size. 3. Save the file and restart nginx with service nginx restart
When entering the admin dashboard/working in the admin dashboard, you may find that the page loads very slowly. One reason is that WordPress uses Google Fonts. Solution: install the Disable Google Fonts plugin (personally tested and confirmed working in 2021.1). (Research suggests another cause is that user avatars fail to load properly, but this has already been fixed in the latest version of WordPress.)
Fundamentals of Digital Methods: Common Functions. 1. Cross Product 2. Vector Normalization 3. Matrix Multiplication 4. Matrix Multiplication.
Use OpenGL to perform various basic operations, including generating a tetrahedron, importing a local model, and applying matrix operations to a model, for a better understanding of digitization methods.
