Tracking Changes in a Database =============== In this article, we will explore the concept of tracking changes in a database. We’ll discuss different approaches to achieve this and focus on one specific solution using system versioning functionality available in MariaDB. Introduction Databases often store critical information that requires auditing or change tracking. This can be achieved through various methods, including triggers, views, and application-level logic. However, these approaches can be cumbersome and may not provide the desired level of flexibility or performance.

Navigation between Storyboard-based View Controllers in iOS In this article, we will explore how to navigate between view controllers in a storyboard-based application. Specifically, we will examine how to display the login screen before navigating to the home screen if the user is not logged in. Overview of iOS App Lifecycle Before diving into the details, it’s essential to understand the iOS app lifecycle and how different components interact with each other.

Understanding the Problem: HTML Parsing and External Entities In this article, we will delve into the world of HTML parsing and external entities, exploring why a seemingly simple task becomes challenging when dealing with specific URLs. We’ll examine the technical aspects involved in loading external entities and how different packages handle them. Introduction to HTML Parsing HTML (HyperText Markup Language) is used for structuring content on the web. It consists of a series of elements, such as <p>, <img>, and <a>, which are combined to create a document.

Reading Multiple Values as Character Vectors from an External File Introduction When working with data from external files, it’s common to encounter variables that have multiple values associated with them. In R, this can be a challenge when trying to load these values into R and perform further analysis or manipulation. In this article, we’ll explore how to read multiple values as character vectors from an external file using the separate_rows function in tidyr.

Understanding View Controller Animations in iOS Introduction to View Controllers and Animations In the world of iOS development, view controllers play a crucial role in managing the user interface and behavior of an application. One of the key features that makes iOS apps visually appealing is the use of animations when switching between different view controllers. In this article, we will explore how to create custom animations inside a UIViewController and discuss the possibility of delaying the transition to ensure that the animation completes before the view controller disappears.

Introduction to Raster Images in R As a technical blogger, it’s essential to understand how to work with raster images in R. In this article, we’ll explore the basics of displaying raster images and provide examples of how to use various functions to achieve this. Understanding Raster Images Raster images are composed of pixels that can be represented as a matrix of values. These images can be stored in various formats such as PNG, JPEG, GIF, etc.

Invalid Parameter When Using rgrass7 with GRASS 7.2.0 and R 3.3.2 Introduction The rgrass7 package in R provides a convenient interface to interact with the GRASS GIS 7.x series, allowing users to leverage the power of GRASS for geographic analysis and processing. In this blog post, we will explore how to use rgrass7 to calculate road network distances between multiple locations using GRASS network tools. Understanding GRASS Network Tools GRASS’s network tools are used to perform spatial analysis on networks, such as calculating shortest paths, network distance, and other topological properties.

Redirecting Links from Facebook’s iPhone App to Other Browsers Introduction In today’s digital landscape, having a seamless user experience is crucial for any website. When it comes to sharing links on social media platforms like Facebook, the native app can sometimes get in the way of achieving this goal. In this article, we’ll delve into the world of browser redirects and explore how to ensure that links shared from Facebook’s iPhone App open in a specific browser, such as Safari.

Partial Least Square Analysis (PLS) with Mixomics: Handling Multiple Blocks of Data Introduction Partial Least Square analysis is a widely used technique for analyzing multivariate data. In the context of mixomics, PLS is used to identify the most relevant variables in complex biological systems. The mixomics package provides an efficient way to perform PLS analysis, but it has limitations when dealing with multiple blocks of data. This article will explore how to extend PLS analysis using the block.

Understanding Multi-Index DataFrames and Dictionary Columns Introduction to Pandas DataFrame Pandas is a powerful library in Python for data manipulation and analysis. It provides a wide range of data structures, including the DataFrame, which is a two-dimensional table of data with rows and columns. A DataFrame is a data structure similar to an Excel spreadsheet or SQL table. Each column represents a variable, while each row represents an observation. In this case, we have a DataFrame df with columns ‘c’, ’d’, and a MultiIndex (also known as a hierarchical index) that contains the values from the dictionaries in the ’d’ column.