Combining plots

To create an overview of a dataset, we may need to combine individual plots into one. In this recipe, we introduce how to combine individual subplots into one plot.

Getting ready

Ensure you have installed and loaded ggplot2 into your R session. Also, you need to complete the previous steps by storing sample_sum in your R environment.

How to do it…

Please perform the following steps to combine plots in ggplot2:

1. First, we need to load the grid library into an R session:

   > library(grid)
   

2. We can now create a new page:

   > grid.newpage()
   

3. Moving on, we can create two ggplot2 plots:

   > g <- ggplot(data=sample_sum, mapping=aes(x=Year_Month, y=Total_Sales, colour = Province ))
   >   plot1 <- g + geom_point(size=5) + ggtitle('Scatter Plot')
   >   plot2 <- g + geom_line(size=3) + ggtitle('Line Chart')
   

4. Next, we can push the visible area with a layout of two columns in one row, using the pushViewport function:

   > pushViewport(viewport(layout = grid.layout(1, 2)))
   

5. Last, we...