title: axis labels with comma but no decimals ggplot
body: <p>I want y-axis labels that have a comma but no decimal points. When I use the 'labels=comma' option in ggplot I get the comma, it also adds in 2 decimals points. When I remove the option I get rid of the decimal points but also lose the comma.</p>
  
  <pre><code>ggplot(birth_decade_data, aes(x = age, y = disp_inc, group = birth_decade, col = birth_decade))+
    geom_point(size=2)+
    geom_line(size=1.05)+
    scale_y_continuous(expand=c(0,0), limits = c(0,80000), breaks=c(20000,40000,60000,80000), labels=comma)+
    scale_x_continuous(expand = c(0.01, 0.01), breaks = c(seq(15,65,5)), limits = c(24,65))
  </code></pre>
  
  <p>Thanks in advance for your help, I've spent ages searching for a solution to this.</p>
  
  <p>Sorry, data looks like this:</p>
  
  <pre><code>&gt; birth_decade_data
  
  year birth_decade disp_inc   age
  1989 1940s           35161 44.1 
  1989 1940s           35161 44.1 
  1989 1950s           31285 34.5 
  1989 1960s           37403 25.0 
  1989 1970s           33117 17.7 
  1989 1980s           26700  7.00
  1999 1940s           39448 54.2 
  1999 1950s           38645 44.3 
  1999 1960s           38617 34.6 
  1999 1970s           41514 24.4 
  1999 1980s           33972 16.7 
  </code></pre>
  
  <p>... more rows</p>
  
  <p><img src="https://i.stack.imgur.com/bWrI3.jpg" alt="chart with commas and decimals"></p>