title: how to plot a map only with lat, long without group in R
body: <p>I am having issues with plotting a UK map. Indeed, I have issues plotting because maybe I do not have a group as a variable. This is the type of data I have.</p>
  <pre><code>lft_j  &lt;- structure(list(journeydate = c(&quot;18/03/2020&quot;, &quot;18/03/2020&quot;, &quot;18/03/2020&quot;, 
  &quot;18/03/2020&quot;, &quot;18/03/2020&quot;, &quot;18/03/2020&quot;), sex = c(&quot;Female&quot;, 
  &quot;Female&quot;, &quot;Female&quot;, &quot;Female&quot;, &quot;Female&quot;, &quot;Female&quot;), ageband = c(&quot;0-18 years&quot;, 
  &quot;0-18 years&quot;, &quot;0-18 years&quot;, &quot;0-18 years&quot;, &quot;0-18 years&quot;, &quot;0-18 years&quot;
  ), ccgcode = c(&quot;E38000001&quot;, &quot;E38000002&quot;, &quot;E38000004&quot;, &quot;E38000005&quot;, 
  &quot;E38000006&quot;, &quot;E38000007&quot;), ccgname = c(&quot;NHS Airedale, Wharfedale and Craven CCG&quot;, 
  &quot;NHS Ashford CCG&quot;, &quot;NHS Barking and Dagenham CCG&quot;, &quot;NHS Barnet CCG&quot;, 
  &quot;NHS Barnsley CCG&quot;, &quot;NHS Basildon and Brentwood CCG&quot;), Total = c(17, 
  27, 27, 43, 30, 42), objectid = c(NA, NA, 1, NA, 2, 3), ccg20cd = c(NA, 
  NA, &quot;E38000004&quot;, NA, &quot;E38000006&quot;, &quot;E38000007&quot;), bng_e = c(NA, 
  NA, 547758, NA, 429979, 564014), bng_n = c(NA, NA, 185109, NA, 
  403330, 194421), long = c(NA, NA, 0.129493, NA, -1.54925001, 
  0.36806801), lat = c(NA, NA, 51.54552841, NA, 53.5257988, 51.62469864
  ), st_lengthshape = c(NA, NA, 40665.2789272553, NA, 125518.601736474, 
  120224.102808673), st_areashape = c(NA, NA, 36091041.104372, 
  NA, 329052050.351673, 263142523.0488)), row.names = c(NA, -6L
  ), class = c(&quot;tbl_df&quot;, &quot;tbl&quot;, &quot;data.frame&quot;))
  
  library(leaflet)
  
  map &lt;- 
    leaflet(lft_j) %&gt;%
    addTiles() %&gt;%
    addMarkers(lng = long, lat = lat, clusterOptions = markerClusterOptions())
  
  map 
  </code></pre>
  <p>This is an error:</p>
  <blockquote>
  <p>Error in resolveFormula(lng, data) : object 'long' not found</p>
  </blockquote>
  <p>This is done in R, with <code>leaflet</code>.</p>