It is of importance to understand that a connected scatterplot is basically an hybrid between a scatterplot and a lineplot. Thus, please visit the related section here and here to get more examples, since the techniques used are very similar.
Please note also that 2 types of connected scatterplot exist. The first is simply a lineplot with dots added on top of it. It takes as input 2 numeric variables only. The second shows the relationship between 2 numerical variables across time. It requires 3 numerical variables as input. Confusing? Visit data-to-viz to clarify.
Connected scatterplots are often used for time series. Remember the R graph gallery offers a dedicated section, with heaps of examples. For instance, here is an interactive chart made with the dygraphs library.
Basic R also allows to build connected scatterplot thanks to the `line()` function. You just need to use the `b` option of the `type` argument. See examples below.
How to add a legend to base R plot
The legend() function allows to add a legend. See how to use it with a list of available customization.
Image on the chart background
The rasterImage function allows to add an image on the background of the chart.
Manage date data
Learn why it is important that your date is recognized at the date format, and how to do so.