title: Unable to fix the x-axis labels in ggplot2 facet_wrap geom_histogram plot
body: <p>Maybe I have missed this in the stackexchange literature, as I'm surprised to find many solutions for adding floating axis labels and adjustments to axes (e.g. <a href="https://stackoverflow.com/questions/13297155/add-floating-axis-labels-in-facet-wrap-plot">add &quot;floating&quot; axis labels in facet_wrap plot</a>), but nothing to solve my issue of overlapping x-axis labels with a facet_wrap and scales = "free".  This one is close, but for an older ggplot version: <a href="https://stackoverflow.com/questions/3445540/overlapping-y-scales-in-facet-scale-free">overlapping y-scales in facet (scale=&quot;free&quot;)</a>. This one may be the answer, to write a function to do such an operation, but I couldn't make it work for me: <a href="https://stackoverflow.com/questions/5380417/is-there-a-way-of-manipulating-ggplot-scale-breaks-and-labels">Is there a way of manipulating ggplot scale breaks and labels?</a></p>
  
  <p>Here is a reproducible example:</p>
  
  <pre><code>v&lt;-runif(1000,min=1000000,max=10000000)
  x&lt;-runif(100,min=0.1,max=1)
  y&lt;-runif(100000,min=0,max=20000)
  z&lt;-runif(100000,min=10000,max=2000000)
  df&lt;-data.frame(v,x,y,z)
  colnames(df)&lt;-c("Order V","Order X","Order Y","Order z")
  
  library(reshape2)
  melt.df&lt;-melt(df[,c(1:4)])
  
  library(ggplot2)
  ggplot(melt.df, aes(x = value)) +
    geom_histogram(bins=50,na.rm=TRUE) +
    facet_wrap(~variable, scales="free") +
    theme_bw()
  </code></pre>
  
  <p>The resulting figure is this: </p>
  
  <p><a href="https://i.stack.imgur.com/DVCeZ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DVCeZ.png" alt="Ex"></a></p>
  
  <p>I have a similar setup, which produces this:</p>
  
  <p><a href="https://i.stack.imgur.com/xjM8I.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/xjM8I.png" alt="Histogram"></a>
  Any help on a cmd to do this, or a function that could set up these x-axis label breaks would be awesome!</p>