Data Engineering and Mining I Name: Paul Brown

AI4OPT - Summer 2022 Due Date: June 23, 2022

1. Interpret the following statement:

rnorm(6, mean = 8, sd = 1.5)

Six observations with a mean of 8 and a standard deviation of 1.5

2. Let n = 10. Write the code to yield the result of the standard error

(se) = sqrt(s2/n).

se <- function(x) sqrt(var(x) / length(x))

3. In the following code, what is the function and what is the argument(s):

convMeters(83.4, “feet”)

ConvMeters is the function and the argument is how many feet in 83.4 meters

4. Use the recycling method to find v1+ v2:

  v1 <- c(2, 5, 3 ,8 , 6)
  v2 <- c(9, 7, 1)
     v1 + v2

5. Factors provide an easy and compact form of handling what kind of data? ________

Categorical

6. Given x <- factor( c(‘adult’, ‘adult’, ‘height’, ‘weight’, ‘adult’, weight’, weight’, ‘height’)

  x <- factor( c(‘adult’, ‘adult’, ‘height’, ‘weight’, ‘adult’, weight’, weight’, ‘height’))
  x
     
  table(x)
  

7. Generate a sequence using the following: rep(12, 6).

  rep(12,6)

Generate a sequence using the following: gl(3,4)

  gl(3,4)

8. In the following statement, what do you call the objects, 2, 4, byrow = TRUE?

2 represents the number of rows and 4 the number of columns

Byrow = TRUE will fill in the table by using values for rows first then followed by columns

results <- matrix(c(10, 30, 50, 43, 56, 21, 30), 2, 4, byrow = TRUE)

  Get a message indicating that length 7 is not a sub-multiple   
  
  results <-  matrix(c(10, 30, 50, 43, 56, 21, 30),  2, 4,  byrow = TRUE)
  

9. Given the vector, a <- c(-8, -3, 0, 5, 10 21, 30), list the results of the following:

  a <- c(-8, -3, 0, 5, 10 21, 30)
  a[a  <= 0  |  a >  10]

  a[c(3, 6)]      

#10. Given the vector, a <- c(-8, -3, 0, 5, 10 21, 30), list the results of the following:
a <- c(-8, -3, 0, 5, 10 21, 30) a[ -3]

  a[ - (1:4)]

11. Given the vector, g <- c(67, 78, 45, 87, 57, 98, 95, 83, 74, 80, 55, 49),

give the results of the following:

  g <- c(67, 78, 45, 87, 57, 98, 95, 83, 74, 80, 55, 49)
  g <- matrix(c( 67, 78, 45, 87, 57, 98, 95, 83, 74, 80, 55, 49), 3, 4)
  

install.packages(“rmarkdown”)