行列：2次元ベクトル

金融のためのR入門

Lore Dirick

Manager of Data Science Curriculum at Flatiron School

行列に入る

my_matrix <- matrix(c(2, 3, 4, 5), nrow = 2, ncol = 2)
my_matrix

     [,1] [,2]
[1,]    2    4
[2,]    3    5

my_matrix2 <- matrix(c(2, 3, 4, 5), nrow = 2, ncol = 2,
                     byrow = TRUE)
my_matrix2

     [,1] [,2]
[1,]    2    3
[2,]    4    5

coerce_me <- matrix(c(2, 3, 4, "hi"), nrow = 2, ncol = 2)

coerce_me

    [,1] [,2]
[1,] "2"  "4" 
[2,] "3"  "hi"

micr <- c(59.20, 59.25, 60.22, 59.95)
ebay <- c(17.44, 18.32, 19.11, 18.22)

cbind(micr, ebay)

      micr  ebay
[1,] 59.20 17.44
[2,] 59.25 18.32
[3,] 60.22 19.11
[4,] 59.95 18.22

rbind(micr, ebay)

 [,1]  [,2]  [,3]  [,4]
59.20 59.25 60.22 59.95
17.44 18.32 19.11 18.22

相関の例

micr <- c(59.20, 59.25, 60.22, 59.95)
ebay <- c(17.44, 18.32, 19.11, 18.22)

cor(micr, ebay)

0.7835704

micr_ebay_matrix <- cbind(micr, ebay)
cor(micr_ebay_matrix)

          micr      ebay
micr 1.0000000 0.7835704
ebay 0.7835704 1.0000000

金融のためのR入門