How to remove rows and columns of a matrix in R
Overview
To understand what a matrix is and how to create a matrix in R, read this shot.
Removing rows and columns from an existing matrix
To remove the row(s) and column(s) of a current matrix in R, we use the c() function.
Parameters of the c() function
The numbers that represent the row number and column number we wish to remove are the parameters. For example:
[-c(1), -c(1)]
The code above specifies the first row and the first column.
Code example
mymatrix <- matrix(c("apple", "banana", "cherry", "orange", "mango", "pineapple"), nrow = 3, ncol =2)# removing the first row an first colummn of the matrixmymatrix <- mymatrix[-c(1), -c(1)]mymatrix
Code explanation
- Line 2: We create a 3x2 matrix (a matrix with 3 rows and 2 columns) called
mymatrix. We use thematrix()function and pass the parameter values of its shape.nrow = 3represents 3 rows, whilencol = 2represents 2 columns. - Line 4: Using the
c()function, we remove the first row and first column[-c(1), -c(1)]from the matrix. - Line 6: We print the modified matrix.