Читать книгу The Big R-Book - Philippe J. S. De Brouwer - Страница 67

Matrix arithmetic allows both base operators and specific matrix operations. The base operators operate always element per element.

Basic arithmetic on matrices works element by element:

M1 <- matrix( c(10:21), nrow = 4, byrow = TRUE) M2 <- matrix(c(:11), nrow = 4, byrow = TRUE) M1 + M2 ## [,1] [,2] [,3] ## [1,] 10 12 14 ## [2,] 16 18 20 ## [3,] 22 24 26 ## [4,] 28 30 32 M1 * M2 ## [,1] [,2] [,3] ## [1,] 0 11 24 ## [2,] 39 56 75 ## [3,] 96 119 144 ## [4,] 171 200 231 M1 / M2 ## [,1] [,2] [,3] ## [1,] Inf 11.000000 6.000000 ## [2,] 4.333333 3.500000 3.000000 ## [3,] 2.666667 2.428571 2.250000 ## [4,] 2.111111 2.000000 1.909091