Summary statistics

If you have a vector of numbers in R, there are many basic commands you can use to compute summary statistics. To illustrate, here is a vector of random numbers:

set.seed(20)
x <- rnorm(100)

Of course, these commands are useful no matter where the numbers came from:

sum(x) # the total of the numbers

[1] 0.4908104

mean(x) # the average of the numbers

[1] 0.004908104

var(x) # the variance

[1] 0.9799034

sd(x) # the standard deviation

[1] 0.9899007

median(x) # the median

[1] -0.02486056

max(x) # the biggest number

[1] 2.208443

min(x) # the smallest number

[1] -2.889718