title: Two Dataset for two secondary axis y in ggplot R
body: <p>first dataset = df</p>
  <pre><code>Date variable value 
  1    A          6
  1    B          2
  1    C          0.8
  2    A          8
  2    B          3
  2    C          2
  3    A          11
  3    B          2
  3    C          4
  </code></pre>
  <p>second dataset = met</p>
  <pre><code>Date variable value
   1     H       140.000
   2     H       70.000
   3     H       150.000
  </code></pre>
  <p>What I am doing, but it is not working</p>
  <pre><code>  ggplot() 
  + geom_line(df, mapping = aes(x=date, y=value, fill=variable, color = variable, linetype=variable)) 
  + geom_line(met, mapping = aes(x=date,y=value, color=&quot;blue&quot;)) 
  + scale_y_continuous(name = &quot;First Axis&quot;, sec.axis = sec_axis(~.1, name=&quot;Second Axis&quot;))
        
  Error: Discrete value supplied to continuous scale
  Warning message: 
  Ignoring unknown aesthetics: fill 
  </code></pre>
  <p>At the same time I have another question. Is it possibile to set 2 ylim? One for the left side and the other one for the right side.</p>
  <p>Thank you in advance</p>