R Homework 1

Moiya Josephs

Question 1

Write a loop that calculates 13-factorial. Bonus - try to do it two different ways (for example use a for loop and a while loop). Do not use the standard factorial function. The goal is to learn about how R uses loops.

fact = 1
for (i in 1:13){
  fact = fact * i
}
fact

## [1] 6227020800

i <- 1
fact1 = 1
while (i<= 13) {
  fact1 = fact1 * i
  i = i + 1
}
fact1

## [1] 6227020800

#check <- factorial(13)

Question 2

Show how to create a numeric vector that contains the sequence from 10 to 50 by 5.

num_vector <- seq(10,50,5)
num_vector

## [1] 10 15 20 25 30 35 40 45 50

Question 3

Create the function “lines” that takes two x,y points and calculates three things: the distance between those two points, the slope and the y intercept. The function should allow you to input both x and y values and give you the three answers.

x1 <- -3
y1 <- 4

x2 <- 6
y2 <- -2

lines <- function(x1,y1,x2,y2) {
  distance <- (sqrt((x2 - x1)^2 +(y2-y1)^2))
  slope <- (y2 - y1)/(x2 - x1)
  y_intercept <- y1 - (slope*x1)
  lines_data <- list(c(distance),c(slope),c(y_intercept))
  names(lines_data) <- c("distance","slope","y_intercept")
  lines_data
}
answer <- lines(x1,y1,x2,y2)
answer

## $distance
## [1] 10.81665
## 
## $slope
## [1] -0.6666667
## 
## $y_intercept
## [1] 2