ASSIGNMENT

Question 1. Create a factor variable called days that contains the days of the week.

# data set containing days of the week
week_days <-c("Monday", "Tuesday", "Wednesday",
              "Thursday", "Friday", "Saturday", "Sunday");week_days

## [1] "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"    "Saturday" 
## [7] "Sunday"

# Creating a factor variable
week_days <-factor(week_days);week_days

## [1] Monday    Tuesday   Wednesday Thursday  Friday    Saturday  Sunday   
## Levels: Friday Monday Saturday Sunday Thursday Tuesday Wednesday

#To test whether a variable is truly a factor or not, we use the class() function
class(week_days)

## [1] "factor"

Question 2. Create an Identity matrix of dimensions 3 by 3.

#Creating a 3 by 3 identity matrix
ident_matrix <- base::diag(3);ident_matrix

##      [,1] [,2] [,3]
## [1,]    1    0    0
## [2,]    0    1    0
## [3,]    0    0    1

#Create another 3 by 3 matrix whose data is a sequence from 1 to 9
matrix_1 <-base::matrix(data = seq(1,9,1), 
                              nrow = 3, ncol = 3);matrix_1

##      [,1] [,2] [,3]
## [1,]    1    4    7
## [2,]    2    5    8
## [3,]    3    6    9

Matrix multiplication of the two matrices

# Multiplying the two matrices by each other
Multiplied_matrix <-ident_matrix %*% matrix_1
Multiplied_matrix

##      [,1] [,2] [,3]
## [1,]    1    4    7
## [2,]    2    5    8
## [3,]    3    6    9

Confirm whether matrix_1 is equal to Multiplied_matrix

# Confirming the equality of the two matrices
equal_matrix <- base::all(matrix_1 == Multiplied_matrix)
equal_matrix

## [1] TRUE

# The output is TRUE, confirming that the second matrix, matrix_1 is equal to the output of the Multiplied matrix, since the first matrix, iden_matrix is identity multiplied with the second matrix, the result will be the same as that of the second matrix.

Question 3. Using the starwars dataset Create a scatterplot using the base graphics of characters height (x-axis) against mass (y-axis).

# Loading the required package
library(dplyr)

## 
## Attaching package: 'dplyr'

## The following objects are masked from 'package:stats':
## 
##     filter, lag

## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union

#Loading the data set to be used
data("starwars")
#Ploting the scatter plot, using the base graphics
scatter_plot <- base::plot(x = starwars$height,
           y = starwars$mass,
           main = "Scatter plot of Height against Mass",
           xlab = "Height", ylab = "Mass", col = "black", pch = 16)

Question 4. Create a histogram of birth year of “starwars”

#Histogram of birth year
attach(starwars)
Hist_birth_year <- graphics::hist(birth_year, main = "Histogram of birth year")

Question 5. Creating the plots using ggplot2 package

library(ggplot2)
#Creating a scatter plot of Mass against Height
scatter_plot_1 <-ggplot(data = starwars, mapping = aes(x = height, y = mass
                                                       )) +
  geom_point(na.rm = TRUE, col = "blue") +
  ggtitle("SCATTER PLOT OF MASS AGAINST HEIGHT") +
  theme_minimal();scatter_plot_1

#Creating a histogram
Hist_birth_year_1 <-ggplot(data = starwars, mapping = aes(x = birth_year)) +
  geom_histogram(na.rm = TRUE) +
  ggtitle("HISTOGRAM OF BIRTH YEAR") +
  theme_minimal();Hist_birth_year_1

## `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.

Question 6. Create a function that takes in a character’s name from the film star wars, and outputs the films in which the character appears.

#Creating a list of the name (characters) and their associated films they appeared in.
name_films <- list(
  "Luke Skywalker" = c("The Empire Strikes Back","A New Hope", "Return of the Jedi", "The Force Awakens", "Revenge of the Sith"),
  "Leia Organa" = c("A New Hope", "The Empire Strikes Back", "Return of the Jedi", "The Force Awakens"),
  "Darth Vader" = c("A New Hope", "The Empire Strikes Back", "Return of the Jedi"),
  "Han Solo" = c("A New Hope", "The Empire Strikes Back", "Return of the Jedi", "The Force Awakens"),
  "Yoda" = c("The Empire Strikes Back", "Return of the Jedi"),
  "Obi-Wan Kenobi" = c("A New Hope", "The Empire Strikes Back", "Return of the Jedi"),
  "R2-D2" = c("A New Hope", "The Empire Strikes Back", "Return of the Jedi", "The Force Awakens"),
  "C-3PO" = c("A New Hope", "The Empire Strikes Back", "Return of the Jedi", "The Force Awakens"),"Roos Tarpals" = c("The Phantom menace", "Padme Amidala" = "The phantom menace","Attack of the clones","Revenge of the Sith"),"Captain Phasma" = c("The force Awakens"), "Sly Moore" = c("Attack of the clones","Revenge of the Sith"), "Raymus Antilles" = c("Revenge of the Sith", "A new Hope")
)
#Creating the function that would output the character names that appeared in a film
Films <- function(character_name) {
  films <- name_films[[character_name]]
  if (is.null(films)) {
    return(paste("Character", character_name, "not found in the film(s)"))
  } else {
    return(films)
  }
}
character_name <- "Raymus Antilles"
films_participated <- Films(character_name);films_participated

## [1] "Revenge of the Sith" "A new Hope"

character_name <-"Luke Skywalker"
films_participated <- Films(character_name);films_participated

## [1] "The Empire Strikes Back" "A New Hope"             
## [3] "Return of the Jedi"      "The Force Awakens"      
## [5] "Revenge of the Sith"