a <- c(10,15,20,12,16,18,17)

b <- c(12,14,23,10,13,19,18)

+1 vote

There is a **barplot()** function in R; you can use it to generate a side-by-side bar plot. You need to create a matrix using two vectors for the plot.

Here is an example using your vectors 'a' and 'b'. I created a matrix 'm' with 2 columns ('a' and 'b') and then transposed it to make it a 10-column matrix. Each column has values from 'a' and 'b'.

a <- c(10,15,20,12,16,18,17)

b <- c(12,14,23,10,13,19,18)

m <- t(matrix(c(a,b), nc=2))barplot(m, beside = TRUE, col = c("blue", "red"), main = "Bar plot example", ylab = "value")

legend("topleft", c("a", "b"), pch = 15, col = c("blue", "red"), bty = "n")

The matrix 'm' looks like the following:

> m

[,1] [,2] [,3] [,4] [,5] [,6] [,7]

[1,] 10 15 20 12 16 18 17

[2,] 12 14 23 10 13 19 18

The above code generates the following bar plot: