Examples
x = 5
abs(x) # x is the argument of the function
## [1] 5
sin(x)
## [1] -0.9589243
exp(x)
## [1] 148.4132
as.character(x)
## [1] "5"
log(x)
## [1] 1.609438
?log # get help for the log function
help(log) # same
x = rnorm(100) # a sample of size 100 from the standard normal distribution
?rnorm # default values: mean = 0 and sd = 1
mean(x)
## [1] -0.01117017
sd(x)
## [1] 0.9549603
median(x)
## [1] -0.1007972
max(x)
## [1] 2.21257
min(x)
## [1] -2.16132
sum(x)
## [1] -1.117017
General form:
myfunction <- function(arg1, arg2 = some_value, ... ){ # arg2 has a default value!
statements
return(object)
}
Example:
get.square <- function(x) {
squared = x^2
return(squared)
}
get.square(2)
## [1] 4
get.square(1.653525)
## [1] 2.734145
get.square(sqrt(2))
## [1] 2
getwd()
## [1] "/home/uwe/Desktop/R-course"
file.exists("plot_norm.R")
## [1] TRUE
source("plot_norm.R")
plot_norm(mean = 2, sd = 1)