CRAN-R_RefreshPart7

This post just follows the previews refresh 6.

WORKING WITH Matrices

Matrix manipulation

Examples

# Construction of a matrix with 3 rows that contain the numbers 1 up to 9

matrix(1:9, byrow = TRUE, nrow = 3)

# Box office Star Wars trilogy 1! The first element: US, the second element: Non-US 

new_hope <- c(460.998, 314.4)

empire_strikes <- c(290.475, 247.900)

return_jedi <- c(309.306, 165.8)

# Box office Star Wars trilogy 1 matrix

star_wars_matrix <- matrix(c(new_hope,empire_strikes,return_jedi), byrow = TRUE, nrow = 3)

# Box office Star Wars trilogy 2! The first element: US, the second element: Non-US 

phantom_menace <- c(474.5,552.5)

attack_clones <- c(310.7,338.7)

revenge_sith <- c(380.3,468.5)

# Box office Star Wars trilogy 2 matrix

star_wars_matrix2 <- matrix(c(phantom_menace,attack_clones,revenge_sith), byrow = TRUE, nrow = 3)

# column names

col_titles <- c("US", "non-US")

movie_names <- c("A New Hope", "The Empire Strikes Back", "Return of the Jedi")

movie_names2 <- c("The Phantom Menace", "Attack of the Clones", "Revenge of the Sith")

ticket_prices <- c(5, 5, 6, 6, 7, 7)

# Box office Star Wars trilogy 1 matrix rows and columns

colnames(star_wars_matrix) <- col_titles

rownames(star_wars_matrix) <- movie_names

star_wars_matrix

# Box office Star Wars trilogy 2 matrix rows and columns

colnames(star_wars_matrix2) <- col_titles

rownames(star_wars_matrix2) <- movie_names2

star_wars_matrix2

# Box office Star Wars trilogy 1 matrix 

box_office_all <- c(461, 314.4, 290.5, 247.9, 309.3, 165.8)

star_wars_matrix <- matrix(box_office_all, nrow=3, byrow = TRUE, dimnames = list(movie_names, col_titles))

# Box office Star Wars trilogy 1 Average non-US revenue per movie

star_wars_non_us_all  <- mean(star_wars_matrix[,2])

# Box office Star Wars trilogy 1 Average non-US revenue of first two movies

star_wars_non_us_some <- mean(star_wars_matrix[1:2,2])

# Box office Star Wars trilogy 1 Estimation of visitors 5$/ticket

star_wars_visitors <- star_wars_matrix/5

# Box office Star Wars trilogy 1 Estimation of visitors per ticket matrix

ticket_prices_matrix <- matrix(ticket_prices, nrow = 3, byrow = TRUE, dimnames = list(movie_names, col_titles))

star_wars_visitor_matrix <- star_wars_matrix / ticket_prices_matrix

# Box office Star Wars trilogy 1 Average number of US visitors

average_us_visitors <- mean(star_wars_visitor_matrix[ ,1])

# Box office Star Wars trilogy 1 Average number of non-US visitors

average_non_us_visitors <- mean(star_wars_visitor_matrix[ ,2])

# Box office Star Wars trilogy 2 matrix 

box_office_all2 <- c(474.5,552.5, 310.7,338.7, 380.3,468.5)

star_wars_matrix2 <- matrix(box_office_all2, nrow=3, byrow = TRUE, dimnames = list(movie_names2, col_titles))

# Box office Star Wars trilogy 2 Average non-US revenue per movie

star_wars_non_us_all2 <- mean(star_wars_matrix2[,2])

# Box office Star Wars trilogy 2 Average non-US revenue of first two movies

star_wars_non_us_some2 <- mean(star_wars_matrix2[1:2,2])

# Box office Star Wars trilogy 2 Estimation of visitors 5$/ticket

star_wars_visitors2 <- star_wars_matrix2/5

# Box office Star Wars trilogy 2 Estimation of visitors per ticket matrix

ticket_prices_matrix2 <- matrix(ticket_prices, nrow = 3, byrow = TRUE, dimnames = list(movie_names2, col_titles))

star_wars_visitor_matrix2 <- star_wars_matrix2 / ticket_prices_matrix2

# Box office Star Wars trilogy 2 Average number of US visitors

average_us_visitors2 <- mean(star_wars_visitor_matrix2[ ,1])

# Box office Star Wars trilogy 2 Average number of non-US visitors

average_non_us_visitors2 <- mean(star_wars_visitor_matrix2[ ,2])

# Box office Star Wars trilogy 1 worldwide box office figures

worldwide_vector <- rowSums(star_wars_matrix)

# Box office Star Wars trilogy 2 worldwide box office figures

worldwide_vector2 <- rowSums(star_wars_matrix2)

# Box office Star Wars trilogy 1 add worldwide_vector as a column to star_wars_matrix

all_wars_matrix <- cbind(star_wars_matrix,worldwide_vector)

# Box office Star Wars trilogy 1 add worldwide_vector as a column to star_wars_matrix

all_wars_matrix2 <- cbind(star_wars_matrix2,worldwide_vector2)

#

all_star_wars <- rbind(star_wars_matrix,star_wars_matrix2)

all_star_wars2 <- rbind(all_wars_matrix,all_wars_matrix2)