Understanding Non-Standard Evaluation in ggplot2 ===================================================== In this post, we will delve into the concept of non-standard evaluation (NSE) in R’s ggplot2 package and how it affects data visualization. We’ll explore a common source of error and provide practical examples to help you work with NSE effectively. What is Non-Standard Evaluation? Non-standard evaluation is a feature of R’s syntax that allows the compiler to evaluate expressions based on the context in which they are used, rather than following traditional syntax rules.

Conditional Smoothed Moving Average in Python ===================================================== In this article, we’ll explore how to create a column that is a conditional smoothed moving average of another column in Python. The condition is that only positive values from another column are included in the rolling average. Background and Problem Statement The problem at hand involves creating a new column in a pandas DataFrame that represents the 14-day smoothed moving average of a specific column (PX_LAST), but with a twist: only positive values from this column are considered.

iOS Twitter Integration with Fabric: A Step-by-Step Guide for iOS 8 and iOS 9 Introduction Twitter integration is a crucial feature for many iOS apps, allowing users to share their thoughts, experiences, and interactions with others on the micro-blogging platform. In this article, we will walk you through the process of integrating Twitter into your iOS app using Fabric, a popular mobile analytics platform developed by Twitter. We will cover both iOS 8 and iOS 9, as these versions have different requirements for Twitter integration.

Accessing Data from an ODBC Connection in C++ This tutorial demonstrates how to access data from a Microsoft Access database using the ODBC (Open Database Connectivity) protocol in C++. We will cover the basics of creating an ODBC connection, executing SQL queries, and retrieving results. Prerequisites A Microsoft Access database file (.mdb or .accdb) The Microsoft Access Driver for ODBC A C++ compiler (e.g., Visual Studio) Step 1: Include Necessary Libraries and Set Up the Environment First, let’s include the necessary libraries:

Step 1: Install and Load Required Libraries To solve the problem, we first need to install and load the required libraries. The dplyr library is used for data manipulation, and the tidyverse library is a collection of packages that work well together. # Install tidyverse install.packages("tidyverse") # Load required libraries library(tidyverse) Step 2: Define Data We then define our dataset in R. The data consists of two columns, dates and ID, where we want to count the occurrences of each ID.

Group by Series or Sequence in R Table of Contents Introduction Problem Statement Solution Overview Step 1: Convert the Data Frame to a Data Table Step 2: Create Two Columns for Time Interval and Time Count Step 3: Group the Rows Based on the Run-Length ID of Time Count Step 4: Combine the Time Intervals and Time Counts Conclusion Introduction R is a powerful programming language for statistical computing and graphics.

Reshape and Group by Operations in Pandas DataFrames Introduction In this article, we will explore how to perform reshape and group by operations on pandas dataframes. We will use a real-world example to demonstrate the different methods available for achieving these goals. Creating a Sample DataFrame Let’s start with creating a sample dataframe that we can work with. | Police | Product | PV1 | PV2 | PV3 | PM1 | PM2 | PM3 | |:-------:|:--------:|:-----:|:-----:|:------:|:-------:|:-------:|:-------:| | 1 | A | 10 | 8 | 14 | 150 | 145 | 140 | | 2 | B | 25 | 4 | 7 | 700 | 650 | 620 | | 3 | A | 13 | 22 | 5 | 120 | 80 | 60 | | 4 | A | 12 | 6 | 12 | 250 | 170 | 120 | | 5 | B | 10 | 13 | 5 | 500 | 430 | 350 | | 6 | C | 7 | 21 | 12 | 1200 | 1000 | 900 | Reshaping and Grouping the DataFrame Our goal is to reshape this dataframe so that the Product column becomes an item name, and we have separate columns for the sum of each year (i.

Loading Views from NIB Files without Adding to View Hierarchy As developers, we often find ourselves working with user interface (UI) components in our applications. One common requirement is to load views from XIB or Storyboard files programmatically. While it’s possible to achieve this by creating a custom UIViewController subclass and adding the desired view to its view hierarchy, there are situations where this approach might not be desirable. In this article, we’ll explore an alternative solution that allows us to load a UIView from a XIB file without adding the controller to the view hierarchy.

Understanding Navigation Bar Frame Size in iOS Introduction In the world of mobile app development, understanding the frame size of a navigation bar can be a challenging task. In this article, we will delve into the details of how to accurately calculate the height of a navigation bar in an iOS application. Background As of iOS 7, Apple introduced a new design language for its navigation bars. The new design features a different frame size compared to previous versions.

Managing Global Data in iOS Apps: Singleton Classes and Beyond Singleton classes have been a topic of discussion in the iOS development community for years. In this article, we’ll delve into the world of singleton classes, explore their benefits and drawbacks, and discuss alternative approaches to managing global data in your iOS apps. What is a Singleton Class? A singleton class is a design pattern that allows a class to have only one instance throughout its lifetime.