Calculating Jumping Average Columns at Every n-th Row in R Using plyr Package

Calculating Average of Rows Which Fulfill Certain Condition in R Using Base R and Tidyverse Packages

Understanding and Implementing the Yearly Evolution of a Variable in R

Handling Moving Averages and NULL Values in TSQL: Best Practices for Resilient Data Analysis

Creating Weekly Cost-per-Sales Table Grouped by Age and Geo Using Conditional Aggregation in PostgreSQL

Counting Items Per Category Above the Average Price in PostgreSQL

Advanced Grouping in R using the `ave()` Function