An object of class matrix (inherits from array) with 4 rows and 4 columns.
Examples
data(matrix)
class(matrix)
#> [1] "matrix" "array"
print(matrix)
#> sample01 sample02 sample03 sample04
#> gene01 1 2 3 4
#> gene02 5 6 7 8
#> gene03 9 10 11 12
#> gene04 13 14 15 16