sum(x) yields the sum of a vector

length(x) yields the number of items in a vector

mean(x) mean value of x

seq(x, y, z) creates a sequence from x, to y, by z

• seq(from=x, to=y, by=z)
• seq(f=x, t=y, b=z)
• in this context, from, to, and by are reserved words
• length.out determines the number of outputs

rep(var, #) creates a vector that repeats var the # of times

• wow = rep('crazy', 3)

  wow -> ('crazy', 'crazy', 'crazy')

?function

• returns a description & use of the given function
• help(func) yields a similar result

round(var, #)

• rounds the var to the # of decimal places

Matrices

• 2Dimensional grouping of values
• Vectors must have the same length & type of values

Example —>

x = c(1,2,3,4,5,6,7,8); y = c(1,2,1,2,1,2,1,2)
mat1 = cbind(x, y)