R Function List

Statistics

• sum
• min, max
• length
• mean
• median
• var
• sd standard deviation
• cor
• lm linear model
• summary
• coef

x = c(4,6,12,9,21,14)
mean(x)
var(x)
median(x)

y = c(10,13,22,15,30,15)
cor(x,y)

Generation

• vector
  • vector("numeric", length = 10) generates a vector having 10 zeros
• seq([from =] a, [to =] b, [by =] stepsize)

seq(1,10,3)

Matrix

• matrix(data,nrow,ncol)
• rbind(first_row, second_row, ...)
• cbind(first_column, second_column, ...)
• solve can give the inverse of the matrix
• dim
  • A matrix can be created directly from a vector by adding a dimension attribute

# Turn a vector into a matrix by adding a dimension attribute
m <- 1:10
dim(m) <- c(2,5)
m

Manipulation

• sort
• head(vec,n)
• tail(vec,n)

x <- c(6, 8, 7, 5, 3, 0, 9)
head(x,2)
tail(x,3)

For Matrices

• t transpose
• det

Logic

• The argument of the below functions is conditional expressions
• which
• any

x <- c(6, 8, 7, 5, 3, 0, 9)
which(x %% 2 == 0) # return indexes
any(x == 10)

Plot

• plot
  • Quick-R: Graphical Parameters
• stem
• hist
• barplot

by zcysxy