HTML tutorial
CSS3 tutorial
Bootstrap tutorial
JavaScript tutorial
JQuery tutorial
AngularJS tutorial
React tutorial
NodeJS tutorial
PHP tutorial
Python tutorial
Python3 tutorial
Django tutorial
Linux tutorial
Docker tutorial
Ruby tutorial
Java tutorial
C tutorial
C ++ tutorial
Perl tutorial
JSP tutorial
Lua tutorial
Scala tutorial
Go tutorial
ASP.NET tutorial
C # tutorial
Compared to matrices, arrays can have more than two dimensions
Compared to matrices, arrays can have more than two dimensions.
We can use the array() function to create an array, and the dim parameter to specify the dimensions:
# An array with one dimension with values ranging from 1 to 24
thisarray <-
c(1:24)
thisarray
# An array with more than one dimension
multiarray <- array(thisarray, dim = c(4, 3, 2))
multiarray
In the example above we create an array with the values 1 to 24.
How does dim=c(4,3,2) work?
The first and second number in the bracket specifies the amount of rows and columns.
The last number in the bracket specifies how many dimensions we want.
Note: Arrays can only have one data type.
You can access the array elements by referring to the index position. You can use the [] brackets to
access the desired elements from an array:
thisarray <- c(1:24)
multiarray <- array(thisarray, dim = c(4, 3, 2))
multiarray[2, 3, 2]
The syntax is as follow: array[row position, column position, matrix level]
You can also access the whole row or column from a matrix in an array, by using the c() function:
thisarray <- c(1:24)
# Access all the items from the first row from
matrix one
multiarray <- array(thisarray, dim = c(4, 3, 2))
multiarray[c(1),,1]
# Access all the items from the first column
from matrix one
multiarray <- array(thisarray, dim = c(4, 3, 2))
multiarray[,c(1),1]
A comma (,) before c() means that we want to access the column.
A comma (,) after c() means that we want to access the row.
To find out if a specified item is present in an array, use the %in% operator:
Check if the value "2" is present in the array:
thisarray <- c(1:24)
multiarray <- array(thisarray, dim = c(4, 3, 2))
2 %in% multiarray
Use the dim() function to find the amount of rows and columns in an array:
thisarray <- c(1:24)
multiarray <- array(thisarray, dim = c(4, 3, 2))
dim(multiarray)
Use the length() function to find the dimension of an array:
thisarray <- c(1:24)
multiarray <- array(thisarray, dim = c(4, 3, 2))
length(multiarray)
You can loop through the array items by using a for loop:
thisarray <- c(1:24)
multiarray <- array(thisarray, dim = c(4, 3, 2))
for(x in multiarray){
print(x)
}