title: using ggmap and ggplotly
body: <p>I am trying to use ggmap with ggplotly, and I am having trouble making the packages work together. A search for the error message got me <a href="https://stackoverflow.com/questions/10930737/ggmap-with-geom-map-superimposed">here</a>. However, I am not sure how the aes inheritance is/could be a problem. The strange thing is that 'myPlot' created with ggmap works just fine in RStudio, but cannot connect to ggplotly. The map data is from <a href="http://www.r-bloggers.com/google-maps-and-ggmap/" rel="nofollow noreferrer">here</a>. </p>
  
  <p>Is it possible to get these two packages working together? (By the way, I cannot tag this as ggplotly, I dont think that package has been referenced on SO before.)</p>
  
  <p><strong>Code</strong></p>
  
  <pre><code>lapply(list("ggplot2", "ggmap", "mapproj", "RCurl", "RJSONIO", "plyr"), 
         require, character.only=TRUE)
  # install.packages("devtools")
  library("devtools")
  # install_github("plotly", "ropensci")
  library(plotly)
  
  mapImageData1 &lt;- get_map(location = c(lon = -0.016179, lat = 51.538525),
                           color = "color",
                           source = "google",
                           maptype = "satellite",
                           zoom = 17)
  
  myMap = ggmap(mapImageData1,
        extent = "device",
        ylab = "Latitude",
        xlab = "Longitude")
  
  py &lt;- plotly("RgraphingAPI", "ektgzomjbx")
  res &lt;- py$ggplotly(gg = p_map)
  </code></pre>
  
  <p><strong>Error Message</strong></p>
  
  <blockquote>
    <p>res &lt;- py$ggplotly(gg = p_map)
        Error in eval(expr, envir, enclos) : object 'lon' not found</p>
  </blockquote>