Rathish_TydeVerse.Rmd

---
title: "TidyVerse Assignment"
author: "Rathish Sasidharan"
date: "4/9/2021"
output: html_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```

## Overview
In this vignette we will explore various tidyverse packages like tidyr,dplyr,ggplot2

Please find the link to the article.

[A Handful Of Cities Are Driving 2016’s Rise In Murders](https://fivethirtyeight.com/features/a-handful-of-cities-are-driving-2016s-rise-in-murders/)

## Prerequisites
Load required packages

```{r message=FALSE}
library(ggplot2)
library(dplyr)
#library(tidyr)

```


### Loading data frame 
Read the  data CSV file into data frames
```{r}
#Read the data from git
murder2016 <- read.csv("https://raw.githubusercontent.com/fivethirtyeight/data/master/murder_2016/murder_2016_prelim.csv")

```

## Subset columns

select {dplyr} function is used to subset  data frame by columns
```{r}
murder2016_colsubset <- murder2016 %>% select(-c('source','as_of'))
```


## Rename columns

rename {dplyr} function is used to rename data frame  columns
```{r}
murder2016_colsubset <- murder2016_colsubset %>% rename(murders_2015=X2015_murders,murders_2016=X2016_murders)
```


## Filter data
filter {dplyr} is used to subset data frame by column value
```{r}
murder2016Fltr<- murder2016_colsubset %>%
    filter(murders_2016 >50 & change >10)
```


## Sort the data
arrange {dplyr} function is used to sort the data frame by column values 
```{r}
murder2016Fltr %>% arrange(murders_2016)
murder2016Fltr %>% arrange(desc(murders_2016))

```



##  Modify columns
mutate {dplyr} - this function is used to create/modify/delete columns
```{r}
murder2016Rt<- murder2016Fltr %>% mutate(increaseRt=change/murders_2016 *100)

murder2016Rt

```


## Plot a graph

bar plot for crime rates

```{r}

murder2016_5row <- head(murder2016Rt,5) 

ggplot(data=murder2016_5row, aes(x=city, y=increaseRt,color=city,fill=city)) +  geom_bar(stat="identity") +labs(title='Crime Rate Across major cities 2016',x='City',y='Crime Rate increase') + theme(axis.text.x = element_text(angle = 90, vjust = 0.5, hjust=1))+geom_text(aes(label=increaseRt), position=position_dodge(width=0.9), vjust=-0.25)

```