R Leaflet - 使用带有 colorNumeric() 调色板的日期或字符图例标签 [英] R Leaflet - use date or character legend labels with colorNumeric() palette
问题描述
我有一个带有 lat/lon 和时间戳的数据集.我希望标记的颜色用连续的调色板显示时间.我正在使用 colorNumeric() 和之前使用 julian(x, "2015-01-01") 创建的朱利安日期.
data = structure(list(timestamp = structure(c(1434056453, 1434148216, 1434153635, 1434245436, 1434358840,1434364288, 1434369611, 1434461435, 1434466830, 1434558725), 类 = c("POSIXct", "POSIXt"), tzone = ""),lon = c(-119.8777, -119.9614, -119.8769, -119.8775, -120.2283,-120.2285, -119.8429, -120.0954, -120.3957, -120.4421),纬度 = c(34.4041,34.376, 34.4061, 34.4021, 34.4696,34.4697, 34.1909, 34.4328, 34.4554, 34.4456),ID = as.factor(c("Z11","Z05","Z01","Z04","Z11","Z04","Z01","Z05","Z05","Z11"))),.Names = c("timestamp", "lon", "lat", "ID"),row.names = c(1:10),类=data.frame")data$julian = as.numeric(julian(data$timestamp, origin = "2015-01-01"))朋友=颜色数字(调色板=彩虹(7)，域=数据$朱利安)m = 传单(数据)m %>% addTiles() %>%addCircles(~lon, ~lat, color = ~pal(julian)) %>%addLegend("bottomright", pal = pal, values = ~julian, title = "Time", opacity = 1)图例将标签显示为数字朱利安日期:我希望它们以2015-01-01"或类似格式显示为正确"日期.
为此，我使用
as.Date(x, origin=as.Date("2015-01-01")) 但插入时它不起作用进入 addLegend() 与
addLegend(pal = pal, values = ~julian,labFormat = labelFormat(transform = ~as.Date(julian, origin=as.Date("2015-01-01"))))有没有办法修改图例标签以显示日期和/或字符?
来自
I have a dataset with lat/lon and a timestamp. I want the color of the markers to show time with a continous palette. I am using colorNumeric() with julian dates earlier created using julian(x, "2015-01-01").
data = structure(list(timestamp = structure(c(1434056453, 1434148216, 1434153635, 1434245436, 1434358840,
1434364288, 1434369611, 1434461435, 1434466830, 1434558725), class = c("POSIXct", "POSIXt"), tzone = ""),
lon = c(-119.8777, -119.9614, -119.8769, -119.8775, -120.2283,
-120.2285, -119.8429, -120.0954, -120.3957, -120.4421),
lat = c(34.4041,34.376, 34.4061, 34.4021, 34.4696,
34.4697, 34.1909, 34.4328, 34.4554, 34.4456),
ID = as.factor(c("Z11","Z05","Z01", "Z04", "Z11", "Z04","Z01","Z05","Z05","Z11"))),
.Names = c("timestamp", "lon", "lat", "ID"),
row.names = c(1:10),
class = "data.frame")
data$julian = as.numeric(julian(data$timestamp, origin = "2015-01-01"))
pal = colorNumeric( palette = rainbow(7), domain = data$julian)
m = leaflet(data)
m %>% addTiles() %>%
addCircles(~lon, ~lat, color = ~pal(julian)) %>%
addLegend("bottomright", pal = pal, values = ~julian, title = "Time", opacity = 1)
The legend shows the labels as numeric, julian dates: I want them to show as "proper" dates in a format like "2015-01-01" or similar.
To do this, I use
as.Date(x, origin=as.Date("2015-01-01")) but it does not work when I insert it into addLegend() with
addLegend(pal = pal, values = ~julian,
labFormat = labelFormat(transform = ~as.Date(julian, origin=as.Date("2015-01-01"))))
Is there a way to modify legend labels so that they show dates and/or characters?
From the leaflet page on legends:
You can also conveniently customize the label appearance by passing labFormat=labelFormat(). labelFormat() has parameters that customize the separator between ranges, the number of digits to render, and prefix/suffix for each label. If your label formatting needs extend beyond what labelFormat() can provide, you can also use a custom function as the labFormat argument; see the Details section in ?addLegend for a description.
Therefore, we can modify the source code for the labelFormat function to include a custom function to convert dates
myLabelFormat = function(
prefix = '', suffix = '', between = ' – ', digits = 3, big.mark = ',',
transform = identity, dates = FALSE ## new 'dates' argument
) {
formatNum = function(x) {
format(
round(transform(x), digits), trim = TRUE, scientific = FALSE,
big.mark = big.mark
)
}
## added 'formatDate' function
formatDate = function(x) {
d = as.Date(x, origin="1970-01-01")
}
function(type, ...) {
switch(
type,
numeric = (function(cuts) {
if(dates){
## will format numbers into dates if dates == TRUE
paste0(formatDate(cuts))
}else{
paste0(prefix, formatNum(cuts), suffix)
}
})(...),
bin = (function(cuts) {
n = length(cuts)
paste0(prefix, formatNum(cuts[-n]), between, formatNum(cuts[-1]), suffix)
})(...),
quantile = (function(cuts, p) {
n = length(cuts)
p = paste0(round(p * 100), '%')
cuts = paste0(formatNum(cuts[-n]), between, formatNum(cuts[-1]))
# mouse over the legend labels to see the values (quantiles)
paste0(
'<span title="', cuts, '">', prefix, p[-n], between, p[-1], suffix,
'</span>'
)
})(...),
factor = (function(cuts) {
paste0(prefix, as.character(transform(cuts)), suffix)
})(...)
)
}
}
Which, as @Nice points out can be shortened to
myLabelFormat = function(...,dates=FALSE){
if(dates){
function(type = "numeric", cuts){
as.Date(cuts, origin="1970-01-01")
}
}else{
labelFormat(...)
}
}
With this new function we can call it as normal
data = structure(list(timestamp = structure(c(1434056453, 1434148216, 1434153635, 1434245436, 1434358840,
1434364288, 1434369611, 1434461435, 1434466830, 1434558725), class = c("POSIXct", "POSIXt"), tzone = ""),
lon = c(-119.8777, -119.9614, -119.8769, -119.8775, -120.2283,
-120.2285, -119.8429, -120.0954, -120.3957, -120.4421),
lat = c(34.4041,34.376, 34.4061, 34.4021, 34.4696,
34.4697, 34.1909, 34.4328, 34.4554, 34.4456),
ID = as.factor(c("Z11","Z05","Z01", "Z04", "Z11", "Z04","Z01","Z05","Z05","Z11"))),
.Names = c("timestamp", "lon", "lat", "ID"),
row.names = c(1:10),
class = "data.frame")
data$julian <- as.numeric(as.Date(data$timestamp))
library(leaflet)
pal = colorNumeric( palette = rainbow(7), domain = data$julian)
m = leaflet(data)
m %>% addTiles() %>%
addCircles(~lon, ~lat, color = ~pal(julian)) %>%
addLegend("bottomright", pal = pal, values = ~julian,
title = "Time", opacity = 1,
labFormat = myLabelFormat(dates=TRUE))
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