Connecting to PostgreSQL with R

• Connecting and reading from mysql
• Executing Queries

R Binary Files

• When we are working with R, we can pass around data or any R objects such as variables, functions using RData files.
• These are binary files that represent R objects
• Lets create an R Object from recipes

save(recipes, file='data/recipes.rdata')
save(users, file='data/users.rdata')

• If you want to load rdata use load function
• We can store multiple multiple objects at one shot

Extract Data From Websites

• Simple HTML Tables:

  • If the data are store neatly in html table we can use readHTMLTable in the XML package to easily extract the data
  • The url of the page is http://khajadatascience.com.s3-website-us-west-2.amazonaws.com/ Refer Here

• Scraping Web Data:

  • Note: Python is very good at scraping web data, so in reality we would use python for this.
  • In R there is a package created to extract data in usable format => rvest
  • Read different html pages information

• Reading json data

  • To read json we have jsonlite library