title: Popup when hover with leaflet in R?
body: <p>My leaflet map looks something like this:</p>
  
  <pre><code>library(sp)
  library(leaflet)
  circleFun &lt;- function(center = c(0,0),diameter = 1, npoints = 100){
    r = diameter / 2
    tt &lt;- seq(0,2*pi,length.out = npoints)
    xx &lt;- center[1] + r * cos(tt)
    yy &lt;- center[2] + r * sin(tt)
    Sr1 = Polygon(cbind(xx, yy))
    Srs1 = Polygons(list(Sr1), "s1")
    SpP = SpatialPolygons(list(Srs1), 1:1)
    return(SpP)
  }
  Circle.Town &lt;- circleFun(c(1,-1),2.3,npoints = 100)
  
  df1 &lt;- data.frame(long=c(0.6,1,1.4), lat=c(-2, -.8, -0.2), other=c('a', 'b', 'c'), VAM=c(10,8,6), 
                    type=c('Public', 'Public', 'Private'), id=c(1:3)) %&gt;% 
    mutate(X=paste0('&lt;strong&gt;id: &lt;/strong&gt;', 
                    id,
                    '&lt;br&gt;&lt;strong&gt;type&lt;/strong&gt;: ',
                    type,
                    '&lt;br&gt;&lt;strong&gt;VAM&lt;/strong&gt;: ',
                    VAM))
  
  # Create a continuous palette function
  pal &lt;- colorNumeric(
    palette = "RdYlBu",
    domain = df1$VAM
  )
  
  leaflet(height = "400px") %&gt;% 
    addTiles() %&gt;%
    addPolygons(data = Circle.Town, color = 'green',  fillOpacity = .7) %&gt;%
    addCircleMarkers(data = df1, lat = ~lat, lng =~long, 
                     radius = ~VAM, popup = ~as.character(X), 
                     fillColor = ~pal(VAM),
                     stroke = FALSE, fillOpacity = 0.8,
                     clusterOptions = markerClusterOptions()) %&gt;% 
    addLegend(position = "topright",
              pal = pal, values = df1$VAM,
              title = "VAM",
              opacity = 1
    ) %&gt;% 
    setView(lng = 1, lat = -1, zoom = 8)
  </code></pre>
  
  <p>Right now, I get a popup when I click one of the circles. Is it possible to get the information when I hover the mouse instead of click? Ideally, I would like something like <a href="http://leafletjs.com/examples/choropleth.html">this</a>.</p>
  
  <p>Thanks!</p>