Occasionally you may want to plot the rows of a matrix in R as individual lines. Fortunately this is easy to do using the following syntax:
matplot(t(matrix_name), type = "l")
This tutorial provides an example of how to use this syntax in practice.
Example: Plot the Rows of a Matrix in R
First, let’s create a fake matrix to work with that contains three rows:
#make this example reproducible set.seed(1) #create matrix data <- matrix(sample.int(50, 21), nrow=3) #view matrix data [,1] [,2] [,3] [,4] [,5] [,6] [,7] [1,] 4 34 14 21 7 40 12 [2,] 39 23 18 41 9 25 36 [3,] 1 43 33 10 15 47 48
Next, let’s use matplot to plot the three rows of the matrix as individual lines on a plot:
matplot(t(data), type = "l")
Each line in the plot represents one of the three rows of data in the matrix.
Note: The matplot function is used to plot the columns of a matrix. Thus, we use t() to transpose the matrix so that we instead plot the rows.
We can also modify the width of the lines and add some labels to the plot:
matplot(t(data), type = "l", lwd = 2, main="Plotting the Rows of a Matrix", ylab="Value")
You can find more R tutorials on this page.