In AndySouth/rmapteach:

Brief list of tips for new(ish) users for Tutorials.

# # indicates a comment

# a 'package' is a collection of functions, data and documentation 

# to install a package from CRAN just need to do once initially 
# & maybe every few months to check for updates
install.packages("ggplot2") # note the quotes

# 'library' to load a package in each new session
library(ggplot2)

# <- to assign things to an object
# c() to concatenate things together
object <- c(1:10)
object2 <- c("apples","oranges")

# things without quotes tend to be objects, whereas with quotes are strings 
# contrast "object" with object

# str(), head() and class() give information about an object
str(object)
head(object)
class(object)

# functions are crucial and are used by a function call like this : 
# function_name(argument1=a, argument2=b)
# arguments to a function can be specified by name or their position in the call  

# dataframes are key for holding data
# they consist of rows and columns
d_f <- data.frame(fruit=c("apples","oranges"), taste_score=c(1,10)) 
d_f
# elements can be accessed by [rownum,colnum]
d_f[2,1]
# missing out either will give you all
d_f[,1]
# which can be used to find the elements that satisfy a condition
which(d_f[,1] =="oranges")

AndySouth/rmapteach documentation built on May 5, 2019, 6:01 a.m.