title: Combine plots with same y-axes different x-axes
body: <p>I am looking into how the bond market reacts to certain events in a seven day window. </p>
  
  <p>Therefore, I want to create a figure that plots the bond yield reactions around the dates. My data looks like following</p>
  
  <pre><code>df &lt;- Date       APP  DE10 
        2014-09-22 0    1.010 
        2014-09-19 0    1.043
        2014-09-18 0    1.081
        2014-09-17 0    1.050
        2014-09-16 0    1.061
        2014-09-15 0    1.067
        2014-09-12 1    1.082
        2014-09-11 0    1.041
        2014-09-10 0    1.047
        2014-09-09 0    0.996
        2014-09-08 0    0.953
        2014-09-05 0    0.928
        2014-09-04 1    0.970
        2014-09-03 0    0.955
        2014-09-02 0    0.931
        2014-09-01 0    0.882
  </code></pre>
  
  <p>APP is a dummy that indicates the date of events. 
  I made the figure below using grid.arrange to put together each country's bond yields plotted as</p>
  
  <pre><code>DE10 &lt;- ggplot(Bond10) + 
     geom_line(aes(x=Date, y=DE10)) +
     labs(title="Germany", x="", y="Bond yield") +
     scale_x_date(limits = as.Date(c('2017-10-23','2017-10-30')), 
     expand=c(0.1,0))+
     geom_vline(aes(xintercept=as.Date("2017-10-26"), color="Event"))+
     scale_y_continuous(limits = c(0.3, 0.6), expand = c(0.1,0)) +  
     theme(legend.position='none',
         axis.text.x=element_blank(),axis.ticks.x=element_blank(), 
         plot.margin=unit(c(0.2,0.2,0,0.2), "cm"))
  </code></pre>
  
  <p>I want the figure below to include multiple lines in each plot under each country plot to see how strong the reactions have been to different events. </p>
  
  <p><a href="https://i.stack.imgur.com/X2OQQ.png" rel="nofollow noreferrer">Figure of bond yields</a></p>
  
  <p><a href="https://i.stack.imgur.com/X2OQQ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/X2OQQ.png" alt="enter image description here"></a></p>