# tips and tricks

## Quick Intro to Reproducible Example in R with reprex

This video quickly introduces you to an amazing R package called reprex that helps in generating Reproducible Example which could be useful in a lot of places like Github issues, Stack Overflow Question and Answers, R-dev mailing list or simply to share your problem with someone or Teaching! Link: https://www.youtube.com/watch?v=hnzrDLf9anw

## One-line Code using viridis for How to change the color scale in ggplot plots

This is a small code snippet to explain how to change the color scale of a ggplot. Continuous Scale Package: viridis Function: scale_fill_viridis_c() (since it’s a continuous scaled value) library(dplyr) library(ggplot2) library(viridis) mtcars %>% tibble::rownames_to_column('Car') %>% tidyr::separate('Car',c('Brand','Model'), remove = F) %>% group_by(Brand) %>% summarize(avg_mpg = mean(mpg)) %>% ggplot() + geom_bar(aes(reorder(Brand,avg_mpg),avg_mpg, fill = avg_mpg), stat = 'identity') + scale_fill_viridis_c() + theme_minimal() + theme(axis.text.x = element_text(angle = 90, hjust = 1)) + labs( title = 'How to arrange Ggplot Bar plot', x = 'mpg') Discrete Scale Package: viridis Function: scale_fill_viridis_d() (since it’s a discrete scaled value)

## How to arrange ggplot (barplot) bars in ascending or descending order

One of the reasons you’d see a bar plot made with ggplot2 with no ascending / descending order - ordering / arranged is because, By default, ggplot arranges bars in a bar plot alphabetically. But most of the times, it would make more sense to arrange it based on the y-axis it represents (rather than alphabetically). It could be your month-wise time series or high-medium-low bars - these are some examples where an alphabetically-sorted bar chart wouldn’t make sense in fact would hinder the process of data communication.

## 3 tidyverse tricks for most commonly used Excel Features

In this post, We’re simply going to see 5 tricks that could help improve your tooling using {tidyverse}. Create a difference variable between the current value and the next value This is also known as lead and lag - especially in a time series dataset this varaible becomes very important in feature engineering. In Excel, This is simply done by creating a new formula field and subtracting the next cell with the current cell or the current cell with the previous cell and dragging the cell formula to the last cell.

## Extract Top Reddit Posts of #rstats in 3 lines of R Code

This post is kept (literally) minimal to demonstrate how simple is this hack using R (of course could be simple in other languages too). This is also to establish a point that R has got use-cases beyond statistics and data-mining. Objective rstats subreddit is one of the popular sources of R-related information / discussion on the internet. We’re trying to extract the top posts of rstats subreddit. Data Format Lucky for us, Reddit offers a json file for every subreddit (also post) and we’ll use that here.