title: Adding regression line text to graph with no intercept ggplot
body: <p>I would like to add the regression line equation and r squared value to my <code>ggplot2</code> scatter plot.</p>
  
  <p>I have found a similar question, which gives the code below, but it doesn't work when I force the regression through the intercept:</p>
  
  <pre><code>library(devtools)
  source_gist("524eade46135f6348140")
  df = data.frame(x = c(1:100))
  df$y = 2 + 5 * df$x + rnorm(100, sd = 40)
  ggplot(data = df, aes(x = x, y = y, label=y)) +
    stat_smooth_func(geom="text",method="lm",hjust=0,parse=TRUE, formula=y~x-1) +
    geom_smooth(method="lm",se=FALSE, formula=y~x-1) +
    geom_point()
  </code></pre>
  
  <p>By adding <code>formula=y~x-1</code>, the text displayed shows the coefficient as the intercept, with the intercept as <code>NA</code>. Is there a fix for this?</p>