title: R - Confidence bands for exponential model (nls) in basic graphics
body: <p>I'm trying to plot a exponential curve (nls object), and its confidence bands. 
  I could easily did in ggplot following the Ben Bolker reply in this 
  <a href="https://stats.stackexchange.com/questions/145799/why-do-i-get-linear-model-when-i-tried-to-fit-exponential-model">post</a>. <a href="https://i.stack.imgur.com/DN5Y0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DN5Y0.png" alt="enter image description here"></a>
  But I'd like to plot it in the basic graphics style, (also with the shaped polygon)  </p>
  
  <pre><code>df &lt;- 
  structure(list(x = c(0.53, 0.2, 0.25, 0.36, 0.46, 0.5, 0.14, 
  0.42, 0.53, 0.59, 0.58, 0.54, 0.2, 0.25, 0.37, 0.47, 0.5, 0.14, 
  0.42, 0.53, 0.59, 0.58, 0.5, 0.16, 0.21, 0.33, 0.43, 0.46, 0.1, 
  0.38, 0.49, 0.55, 0.54), 
  y = c(63, 10, 15, 26, 34, 32, 16, 31,26, 37, 50, 37, 7, 22, 13, 
  21, 43, 22, 41, 43, 26, 53, 45, 7, 12, 25, 23, 31, 19, 
  37, 24, 50, 40)), 
  .Names = c("x", "y"), row.names = c(NA, -33L), class = "data.frame")
  
  m0 &lt;- nls(y~a*exp(b*x), df, start=list(a= 5, b=0.04))
  summary(m0)
  
  coef(m0)
  #   a        b 
  #9.399141 2.675083 
  
  df$pred &lt;- predict(m0)
  library("ggplot2"); theme_set(theme_bw())
  g0 &lt;- ggplot(df,aes(x,y))+geom_point()+
          geom_smooth(method="glm",family=gaussian(link="log"))+
          scale_colour_discrete(guide="none")
  </code></pre>
  
  <p>Thanks in advance!</p>