Simply add these to your ggplot:
+ scale_x_continuous(expand = c(0, 0), limits = c(0, NA)) +
scale_y_continuous(expand = c(0, 0), limits = c(0, NA))
df <- data.frame(x = 1:5, y = 1:5)
p <- ggplot(df, aes(x, y)) + geom_point()
p <- p + expand_limits(x = 0, y = 0)
p # not what you are looking for
p + scale_x_continuous(expand = c(0, 0), limits = c(0,NA)) +
scale_y_continuous(expand = c(0, 0), limits = c(0, NA))
Lastly, take great care not to unintentionally exclude data off your chart. For example, a position = 'dodge'
could cause a bar to get left off the chart entirely (e.g. if its value is zero and you start the axis at zero), so you may not see it and may not even know it's there. I recommend plotting data in full first, inspect, then use the above tip to improve the plot's aesthetics.
Source: Stackoverflow.com