Adjust the position of title in ggplot2

We will use hjust argument to adjust the title position in ggplot

library(tidyverse)

## Warning: package 'tidyverse' was built under R version 3.3.3

## Loading tidyverse: ggplot2
## Loading tidyverse: tibble
## Loading tidyverse: tidyr
## Loading tidyverse: readr
## Loading tidyverse: purrr
## Loading tidyverse: dplyr

## Warning: package 'ggplot2' was built under R version 3.3.3

## Warning: package 'tibble' was built under R version 3.3.3

## Warning: package 'tidyr' was built under R version 3.3.3

## Warning: package 'readr' was built under R version 3.3.3

## Warning: package 'purrr' was built under R version 3.3.3

## Warning: package 'dplyr' was built under R version 3.3.3

## Conflicts with tidy packages ----------------------------------------------

## filter(): dplyr, stats
## lag():    dplyr, stats

# Working with mtcars dataset

ggplot(data=mtcars,aes(x=disp,y=mpg)) + geom_point(col="blue") + xlab("Disp") +
  ylab("mpg") + ggtitle("Scatter plot") + theme_bw() + theme(plot.title = element_text(hjust=0.5))

# hjust=0.5 means at the center, while 1 (right) and 0 (left)