How to set custom color in AddTimeLine - r

Question

I am trying to create a time line plot using leaflet and leaftime packages. I want to set custom color in addTimeline to specify each point to his groups, as follows:
library(leaflet)
library(leaftime)
library(geojsonio)
power_d <- data.frame(
"Latitude" = c(
33.515556, 38.060556, 47.903056, 49.71, 49.041667, 31.934167,
54.140586, 54.140586, 48.494444, 48.494444
),
"Longitude" = c(
129.837222, -77.789444, 7.563056, 8.415278, 9.175, -82.343889,
13.664422, 13.664422, 17.681944, 17.681944
),
"start" = seq.Date(as.Date("2015-01-01"), by = "day", length.out = 10),
"end" = seq.Date(as.Date("2015-01-01"), by = "day", length.out = 10) + 1,
color_temp=rep(c("red","blue","green"),len=10)
)
power_geo <- geojsonio::geojson_json(power_d ,lat="Latitude",lon="Longitude")
leaflet() %>%
addTiles() %>%
setView(44.0665,23.74667,2) %>%
addTimeline(data = power_geo,
timelineOpts = timelineOptions(
styleOptions = styleOptions(
radius = 5,
color=color_temp,
fillColor = color_temp,
fillOpacity = 1
)
)
)
Unfortunately I got following error:
Error in lapply(x, f) : object 'color_temp' not found
I also try replacing color_temp with power_d$color_temp, the code run without error, but the color of points do not change. The color arguments not work in above code, why? and how to fix it?

Answer 1

It doesn't seem as if you can pass a vector of colours with the standard styleOptions, however, an example from the help page for ?addTimeline show how you can add colours based on the data using a little JavaScript (which thankfully is provided in the example).
Using the example that starts "# to style each point differently based on the data" you need to change it slightly to point to your colour vector e.g. change data.properties.color to data.properties.color_temp. Running the code below leads to
# code
leaflet(power_geo) %>%
addTiles() %>%
setView(44.0665,23.74667,2) %>%
addTimeline(
timelineOpts = timelineOptions(
styleOptions = NULL,
pointToLayer = htmlwidgets::JS(
"
function(data, latlng) {
return L.circleMarker(
latlng,
{
radius: 25,
color: data.properties.color_temp,
fillColor: data.properties.color_temp,
fillOpacity: 1
}
);
}
"
)
)
)