Assignment 1 1/16/13

Intro to R

1 + 3

## [1] 4

a <- 1 + 3
a

## [1] 4

Using Functions in R

rain <- c(16, 18, 14, 22, 27, 17, 19, 17, 17, 22, 20, 22)
mean(rain)

## [1] 19.25

sum(rain)

## [1] 231

length(rain)

## [1] 12

rain - mean(rain)

##  [1] -3.25 -1.25 -5.25  2.75  7.75 -2.25 -0.25 -2.25 -2.25  2.75  0.75
## [12]  2.75

rainDeviations <- rain - mean(rain)
rainDeviations^2

##  [1] 10.5625  1.5625 27.5625  7.5625 60.0625  5.0625  0.0625  5.0625
##  [9]  5.0625  7.5625  0.5625  7.5625

sqrt(rain)

##  [1] 4.000 4.243 3.742 4.690 5.196 4.123 4.359 4.123 4.123 4.690 4.472
## [12] 4.690

rainDeviationsSquared <- rainDeviations^2
mean(rainDeviationsSquared)

## [1] 11.52

meansqudev <- mean(rainDeviationsSquared)
sqrt(meansqudev)

## [1] 3.394

Writing Functions in R

myMean <- function(rain) {
    return(sum(rain)/length(rain))
}
myMean(rain)

## [1] 19.25

mean(rain)

## [1] 19.25

rain/0.3937

##  [1] 40.64 45.72 35.56 55.88 68.58 43.18 48.26 43.18 43.18 55.88 50.80
## [12] 55.88

in_to_cm <- function(rain) {
    return(rain/0.3937)
}
in_to_cm(rain)

##  [1] 40.64 45.72 35.56 55.88 68.58 43.18 48.26 43.18 43.18 55.88 50.80
## [12] 55.88

Assignment 1

stdev <- function(rain) {
    return(sqrt(mean((rain - mean(rain))^2)))
}
stdev(rain)

## [1] 3.394