# Extract Values from Matrix by Column & Row Names in R (3 Examples)

In this article, Iâ€™ll show how to **get certain column and row values using column and row names of a matrix** in the R programming language.

The content of the article looks as follows:

So now the part you have been waiting for â€“ the examplesâ€¦

## Example Data

First, weâ€™ll have to create some data that we can use in the examples below.

my_matrix <- matrix(1:15, ncol = 5) # Create example matrix colnames(my_matrix) <- paste0("Col", 1:5) rownames(my_matrix) <- paste0("Row", 1:3) my_matrix # Print example matrix # Col1 Col2 Col3 Col4 Col5 # Row1 1 4 7 10 13 # Row2 2 5 8 11 14 # Row3 3 6 9 12 15

As you can see based on the previously shown RStudio console output, our example matrix has three rows and five columns. The rows of our matrix are named Row1 â€“ Row3 and the variables are named Col1 â€“ Col5.

Letâ€™s extract some values of our matrix!

## Example 1: Extracting Certain Columns of Matrix by Column Names

In Example 1, Iâ€™ll illustrate how to use the variable names of our matrix to get the values of certain columns.

Consider the following R code:

my_matrix_col <- my_matrix[ , c("Col2", "Col5")] # Extract columns my_matrix_col # Print updated matrix # Col2 Col5 # Row1 4 13 # Row2 5 14 # Row3 6 15

Have a look at the previous output of the RStudio console: We have extracted all row values of the columns Col2 and Col5.

## Example 2: Extracting Certain Rows of Matrix by Row Names

In Example 2, Iâ€™ll show how to extract certain rows by using the row names of our matrix:

my_matrix_row <- my_matrix[c("Row2", "Row3"), ] # Extract rows my_matrix_row # Print updated matrix # Col1 Col2 Col3 Col4 Col5 # Row2 2 5 8 11 14 # Row3 3 6 9 12 15

We have extracted all columns, but only the second and third row were kept.

## Example 3: Extracting Certain Columns & Rows of Matrix by Column & Row Names

Example 3 explains how to use column and row names simultaneously to extract specific data points from our matrix:

my_matrix_col_row <- my_matrix[c("Row1", "Row3"), # Extract columns & rows c("Col1", "Col4", "Col5")] my_matrix_col_row # Print updated matrix # Col1 Col4 Col5 # Row1 1 10 13 # Row3 3 12 15

Looks good!

## Video, Further Resources & Summary

Do you need further information on the R programming codes of the present article? Then you could watch the following video of my YouTube channel. Iâ€™m showing the R codes of this post in the video.

In addition, you could have a look at the other articles of this website:

- Change Row Names of Data Frame or Matrix in R
- Convert Row Names into Column of Data Frame
- Convert Values in Column into Row Names of Data Frame
- Select Data Frame Columns by Logical Condition
- R Programming Tutorials

In this tutorial, I explained how to **extract particular values of a matrix** in the R programming language. Let me know in the comments, in case you have any additional questions.