[R-sig-Geo] Adding colour to polylines in Leaflet

[Dhiraj Khanna]

I am working with shipping data where I get the dynamic parameters of a
ship like its position, speed, heading and rate of turn. I am then trying
to plot this on a leaflet map and trying to colour the polylines based on
the speed, but it always shows up in the same colour. Here’s some sample
data:


structure(list(lat = c(51.88783, 51.8878441, 51.887825, 51.88659,
51.8866959, 51.8874931, 51.89359, 51.8941269, 51.8977051, 51.8994331,
51.90773, 51.91324, 51.91604, 51.9216652, 51.93353, 51.9419365 ), lon
= c(4.28763342, 4.287635, 4.28765154, 4.29007339, 4.29562664,
4.29917, 4.30641174, 4.30561829, 4.29263353, 4.284498, 4.261132,
4.24711847, 4.241075, 4.23262, 4.21523666, 4.1927), rateOfTurn = c(0L,
 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L),
sogKts = c(0, 0, 0, 2.1, 3.4, 4.6, 3.5, 3.8, 7.4, 7.9, 8.8,      9.1,
9.2, 9.2, 9.3, 9.3), cog = c(15, 15, 15, 122.2, 70.4,      70, 323.2,
315.3, 289.3, 290.9, 303.8, 303.7, 308.9, 324.5,      304.9, 301.4),
heading = c(163, 162, 163, 106, 71, 71, 303,      298, 289, 294, 303,
303, 310, 324, 304, 302), timestamp = c("2018-07-19T05:27:34",
"2018-07-19T05:39:35", "2018-07-19T05:45:34", "2018-07-19T05:57:37",
   "2018-07-19T06:02:48", "2018-07-19T06:04:49",
"2018-07-19T06:12:51",      "2018-07-19T06:13:32",
"2018-07-19T06:19:08", "2018-07-19T06:21:41",
"2018-07-19T06:28:42", "2018-07-19T06:32:50", "2018-07-19T06:34:37",
   "2018-07-19T06:37:41", "2018-07-19T06:43:49", "2018-07-19T06:50:09"
    ), Color = c("red", "red", "red", "red", "orange", "orange",
"orange", "orange", "orange", "orange", "yellow", "yellow",
"yellow", "yellow", "yellow", "yellow")), row.names = 32:47, class =
"data.frame")

This is the code I have tried which doesn’t work:-

map <-  leaflet(x) map <- addTiles(map) for( Color in
levels(as.factor(x$Color))){   map <- addPolylines(map,
lng=~lon,lat=~lat,data=x[x$Color==Color,], color=~Color) } map

Regards
Dhiraj Khanna
Mob:09873263331

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