title: Plot lineplot with a "year-less" date-axis
body: <p>I have crime data of the years 2018-2020. Each row represents one crime. For the sake of this example let's assume that there are two variables <code>crimetype</code> (e.g. theft, robbery) and <code>date</code> (when the crime was committed).</p>
  
  <p>Some sample data:</p>
  
  <pre><code>
  data &lt;- data.frame(date= sample(seq(as.Date('2018/01/01'), as.Date('2020/12/31'), by="day"),10000, replace=T),
                     crimetype = sample(c("A", "B", "C"), 100000, replace=T))
  </code></pre>
  
  <p>My goal is to create a lineplot for, let's say, type "A" crimes. On the x-axis there should be the date (from january 1st to december 31st), on the y-axis there should be the number of crimes per day. However, as I want the three lines (one for each year) to be shown on top of each other, so that I can compare them, there should be no year on the x-axis. Or it should not be displayed at least.</p>
  
  <pre><code>  ^        . . . . . .
    |     . .           .
    | . .                .
  n |                      . 2018
    |      - - -
    | - - -      - - - - - 2019
    | = = =
    |       = = = = = = = = 2020
    |
    -------------------------------------&gt;
     Jan-1                Dec-31                        
  </code></pre>
  
  <p>I was trying to create a new date-variable with all the dates in the same year (here 2020).</p>
  
  <pre><code>data &lt;- data %&gt;% mutate(daymonth = substr(date, 5, length(date)),
                          date_new = as.Date(paste("2020", daymonth, sep="")),
                          daymonth = NULL)
  </code></pre>
  
  <p>Is there a better way to do this and how can I plot the graph?</p>
  
  <pre><code>data_plot &lt;- data %&gt;% filter(crimetype == 'A')
  ggplot(data = data_plot, aes(x = date_new, y = ?, color=format(date, "%Y")) + geom_line()
  </code></pre>