How to get image iconMarker working for plotGoogleMaps R?

Question

What am I trying to do: I am trying to plot 2 groups of points (vessels) with different icons on a nice interactive map. (The vessels have longitude and latitude) The interactivity is important!

The code will actually go inside an iframe in a shiny application.

I set up an example vessel data set (two groups of 5), and plot them onto 2 separate layers. I have been doing a bit of research and plotGoogleMaps seemed like a good package to go to.

library(plotGoogleMaps)
vessels = data.frame(id = c(1:10)
                     , lat = c(22.0959, 22.5684, 21.9189, 21.8409, 22.4663, 22.7434, 22.1658, 24.5691, 22.4787, 22.3039)
                     , lon = c(114.021, 114.252, 113.210, 113.128, 113.894, 114.613, 113.803, 119.730, 113.910, 114.147))
group1 = vessels[1:5,]
group2 = vessels[6:10,]

coordinates(group1) = ~ lon + lat
proj4string(group1) = CRS("+proj=longlat +datum=WGS84")
group1 <- SpatialPointsDataFrame( group1 , data = data.frame( ID = row.names( group1 ) ))

coordinates(group2) = ~ lon + lat
proj4string(group2) = CRS("+proj=longlat +datum=WGS84")
group2 <- SpatialPointsDataFrame( group2 , data = data.frame( ID = row.names( group1 ) ))


m <- plotGoogleMaps(group1, legend = FALSE, layerName = "Vessels 1"
                    , add = T, iconMarker='http://maps.google.com/mapfiles/kml/shapes/placemark_circle.png', mapTypeId='ROADMAP')
m <- plotGoogleMaps(group2,legend = FALSE, layerName = "Vessels 2"
                    , previousMap = m , add = F
                    , iconMarker = 'http://maps.google.com/mapfiles/kml/shapes/placemark_circle.png'
                    , filename = "out.htm")

Could anyone please tell me where the code is going wrong? Any constructive ideas are appreciated as well!

Result:

enter image description here

The icon marker has not actually been picked up as you can see it on the result. I would like to use a custom image. Thank you for your help

I ran your code in a fresh R session, and I got a plot with some points on it. I think you need to tell us where the results are going wrong. What do you expect, and what do you get? I get something that looks plausibly like what you might want. — Gregor Thomas
I would have attached a picture (but lack of reputation does not allow it). I am getting the default icon markers (with numbers on them). Instead of the ones I referenced in the code: maps.google.com/mapfiles/kml/shapes/placemark_circle.png — Peter
Oh, that makes sense. You should probably edit that into your question explicitly. Also feel free to upload something to imgur, someone with more rep can edit it into your question. — Gregor Thomas

Milan Kilibarda Milan Kilibarda · Accepted Answer · 2015-05-12T05:44:00

You need a little modification on the last 2 lines of code, and than you will get what you want.

m <- plotGoogleMaps(group1, legend = FALSE, layerName = "Vessels 1"
                , add =T,
iconMarker=rep('http://maps.google.com/mapfiles/kml/shapes/placemark_circle.png',nrow(group1) ), 
mapTypeId='ROADMAP', filename = "out.htm")

m <- plotGoogleMaps(group2,legend = FALSE, layerName = "Vessels 2"
                , previousMap = m , add = F
                , iconMarker = rep('http://maps.google.com/mapfiles/kml/shapes/placemark_circle.png',nrow(group2) )
                , filename = "out.htm")

enter image description here

How to get image iconMarker working for plotGoogleMaps R?

1 Answers