基于R中数据密度的着色

Question

I have a data frame which every row has a numeric column. I want to allocate different colors based on this column. The numbers of this column range from 1 to 152. I used this function:

colors <- function(df,sp) {
check<-colorRampPalette(c("green","red"))(152)
color <- c() 
for (i in 1:nrow(sp))
{
  color <-c(color, check[df$n[df$id==as.numeric(sp[i,]$ID)])
} 
return(color)
} 

So the color is divided equally into 152 pieces.However, data in this column are mostly small (mostly are 1), the histogram is like this

If I used this code the color is mostly green-like and hardly see a red-like.

I am using this function to change the line color in the leaflet:

leaflet() %>%
...
addPolylines(data = data,weight = '1', color=colors(nodes,data))

So how can I change this function to make the color can be evenly distributed, so it can generate more red-like color, not mostly green?

Answer 1

We can use the function

colorQuantile

From the library leaflet colorNumeric . It maps continuous numeric data via the quantile function.

colorQuantile(palette, domain, n = 4, probs = seq(0, 1, length.out = n
+ 1), na.color = "#808080", alpha = FALSE, reverse = FALSE,
right = FALSE)