Presenting a Modal View Controller in viewDidAppear Instead of viewDidLoad As developers, we’ve all been there - we’re building an iPhone app, and everything is going great until we encounter a frustrating issue. In this case, the question comes from a user who’s struggling to present a modal view controller in their app. The user has a HomeViewController and ContentViewController, where they’re saving values in ContentViewController using NSUserDefaults. They want to display different views based on these saved values when the app restarts.

Calculating Percentage in a DataFrame: A More Efficient Approach As data analysts and scientists, we often work with large datasets to extract insights and make informed decisions. In this article, we’ll explore the most efficient way to calculate percentages in a Pandas DataFrame. Understanding the Problem The problem at hand is calculating the percentage of done trades compared to the total number of records in the original dataframe. We have a filtered dataframe df with only the rows where 'state' equals 'Done'.

Converting Daily Data to Monthly Averages with xts in R As a data analyst, working with time series data is a common task. When dealing with daily data, it’s often necessary to convert it into monthly or yearly averages for easier analysis and comparison. In this article, we’ll explore two ways to achieve this conversion using the xts package in R. Introduction to xts The xts package provides classes and methods for time series objects, allowing for efficient manipulation and analysis of temporal data.

Working with Null Values in SQL Queries: A Deep Dive In this article, we will explore the nuances of working with null values in SQL queries. We will delve into the ways to handle null values, including using conditional statements like CASE to check for nullity and present a practical example. Understanding Null Values in SQL Before we dive into solving the problem at hand, it’s essential to understand what null values are in the context of SQL.

Understanding the useDynLib() Function in R Package Namespace Files When building an R package that relies heavily on shared objects compiled by a Makefile, it’s essential to understand how to use the useDynLib() function correctly in the namespace file. This function plays a crucial role in linking the shared object to the package, but its usage can be tricky. In this article, we’ll delve into the details of useDynLib(), explore common pitfalls, and provide practical advice on how to get it right.

SQL Server 2008 R2: Multiple Conditions on the Same Column with AND Operator Introduction In this article, we will explore how to apply multiple conditions on the same column in SQL Server 2008 R2 using the AND operator. We will also discuss the different methods available to achieve this and provide examples of each. Understanding SQL Server 2008 R2 Before diving into the topic at hand, it is essential to understand the basics of SQL Server 2008 R2.

Understanding the Issue with R’s tryCatch Function ===================================================== When working with file operations in R, it is not uncommon to encounter issues where a script crashes due to errors in certain files. This can be frustrating, especially when dealing with large numbers of files and limited resources. In this article, we will explore how to use the tryCatch function in R to handle such situations and identify the problematic files.

DeepNet to MXNet Error Translation: A Step-by-Step Guide In this article, we will explore the translation process from deepnet (Sae) to mxnet (MxMLP). We will delve into the details of both frameworks and identify the key differences that lead to the error message. Introduction to DeepNet and MXNet DeepNet is a R package for neural networks, while MXNet is an open-source machine learning framework developed by Apache. Both frameworks have their strengths and weaknesses, but they share some commonalities that make them interchangeable in certain situations.

Overview of Plumber API Deployment on AWS EC2 or Alternative Options As a developer, it’s essential to consider the best practices for deploying a production-ready API on Amazon Web Services (AWS). In this article, we’ll explore how to keep a Plumber API running on an AWS EC2 instance and discuss alternative deployment options. What is Plumber? Plumber is an open-source framework for building web APIs in R. It provides a simple way to create RESTful APIs using the R programming language.

Understanding UNION and Subqueries in MySQL As a developer, working with complex queries can be challenging. One common issue is combining the results of multiple subqueries into a single column using UNION. While this construct is straightforward, it often requires duplicating the FROM clause for each query. However, what if you want to simplify this process and avoid using temporary tables or Common Table Expressions (CTEs)? In this article, we will explore how to UNION over the result of a subquery without relying on temporary tables or CTEs.