R

R Beginners Functions

R is another open source programmer language, inspired from S language which was written for Statistician who wanted to do Data Analytics and Data Science.

Here are some beginner functions you can use to write start working with.

  • getwd() to check there current working directory
  • setwd("~/Desktop/") to change the current working directory location
  • dir() to check the files in that directory.
  • c or array fns to create an array
  • rbind to combine two arrays
  • sort to sort values
  • seq to generate numbers in a range(range fns in Python)
  • which.max returns the index of the max element in the array
  • data.frame to create a data frame from arrays
  • read.csv to create a data frame from csv
  • write.csv(WHO_Europe, "WHO_Europe.csv”) to save the file
  • match is like a counting no.of times a value occurred in a column
  • as.numeric to convert boolean/logical operator values to numeric

some constants

  • NA : Not Available (i.e. missing values)
  • NaN : Not a Number (e.g. 0/0)
  • Inf: Infinity
  • -Inf : Minus Infinity.

dataframe

  • names to print all the column names in a data frame
  • $ to check a data frame each column’s values
  • dim to check the shape of the data frame
  • str to check the structure/type of object/variable
  • summary to check summary of data frame
  • subset to filter the required data.
  • table is like summary of a categorical variables
  • tapply(WHO$Over60, WHO$Region, max) is like pivot
  • tapply(WHO$LiteracyRate, WHO$Region, max, na.rm=TRUE) excluding the NA’s

Check/remove Locals variables

  • ls() to check all local variables
  • rm(..) to remove variables

__Plotting __

  • hist to do histogram plots
  • plot for scatter plots/ linear plots
  • boxplot(WHO$LifeExpectancy ~ WHO$Region) to box plot Life Expectancy for each region
    • internal optional labels are xlab, ylab, name

Date/Format

  • as.Date(strptime(, "%m/%d/%y %H:%M”)) to convert string into Date Type
  • format to convert strings into string

BUILT-IN FUNCTION

EXAMPLES:

MAP, REDUCE, FILTER, FIND, NEGATE:

Sample Data Files:

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