通过绘制值和颜色来创建颜色条

Question

我通过为特定颜色指定值来创建自己的色阶，如下所示：（Dataframe = df_avg，values column = pmplot，color column = gr_colour）

df_avg$gr_colour[df_avg$pmplot<5] <- "palegreen4"
df_avg$gr_colour[df_avg$pmplot>=5 & df_avg$pmplot<10] <- "palegreen3"
df_avg$gr_colour[df_avg$pmplot>=10 & df_avg$pmplot<12] <- "palegreen2"
df_avg$gr_colour[df_avg$pmplot>=12 & df_avg$pmplot<14] <- "palegreen1"
df_avg$gr_colour[df_avg$pmplot>=14 & df_avg$pmplot<16] <- "lightgoldenrod1"
df_avg$gr_colour[df_avg$pmplot>=16 & df_avg$pmplot<18] <- "khaki1"
df_avg$gr_colour[df_avg$pmplot>=18 & df_avg$pmplot<20] <- "goldenrod1"
df_avg$gr_colour[df_avg$pmplot>=20 & df_avg$pmplot<22] <- "darkgoldenrod1"
df_avg$gr_colour[df_avg$pmplot>=22 & df_avg$pmplot<24] <- "darkorange1"
df_avg$gr_colour[df_avg$pmplot>=24 & df_avg$pmplot<26] <- "darkorange2"
df_avg$gr_colour[df_avg$pmplot>=26 & df_avg$pmplot<28] <- "orangered1"
df_avg$gr_colour[df_avg$pmplot>=28 & df_avg$pmplot<30] <- "orangered3"
df_avg$gr_colour[df_avg$pmplot>=30] <- "red3"

每个PM_value都有一个相应的纬度和经度值，我想将其绘制为沿ggmap的点。我的数据帧的开头如下所示：

Lat            Long           PM_value      colour
-33.92426      151.2280       19.6          goldenrod1
-33.92406      151.2278       16.8          khaki1
-33.92386      151.2278       13.1          palegreen1

我目前正在如下绘制此地图：

map = get_map(location = c(lon = 151.22528, lat = -33.91413), zoom = 15, maptype = "roadmap")

ggmap(map) + geom_point(data = df_avg, aes(x = df_avg$Long, y = df_avg$Lat), col = df_avg$gr_colour, cex = 4)

我想创建一个颜色条，其图例对应于PM_values，颜色条对应于匹配的颜色（在“颜色”列中）。

到目前为止，我已经创建了一个渐变颜色，如下所示：

colfunc <- colorRampPalette(c("palegreen4", "palegreen3", "palegreen2", "palegreen1", "lightgoldenrod1","khaki1", "goldenrod1", "darkgoldenrod1", "darkorange1", "darkorange2", "orangered1", "orangered3"))

plot(rep(1,100),col=colfunc(100),pch=15,cex=3)

如何在此ggmap中创建颜色条以使颜色与“PM_value”中的相应值匹配？

Answer 1

你可以尝试一下吗？

library(tidyverse)
pal <- c("palegreen4", "palegreen3", "palegreen2", "palegreen1", "lightgoldenrod1","khaki1", "goldenrod1", "darkgoldenrod1", "darkorange1", "darkorange2", "orangered1", "orangered3","red3")
Breaks <- c(0,5,seq(10,30,2))
set.seed(123)
tibble(PM_value=sample(1:50, 500, T)) %>% 
  mutate(col=cut(PM_value, breaks = c(0,5,seq(10,30,2), max(PM_value)), labels = c(0,5,seq(10,30,2)))) %>% 
  mutate(col=as.numeric(as.character(col))) %>% 
  ggplot(aes(x=seq_along(PM_value),y=PM_value, color=col)) + 
    geom_point() + 
    scale_colour_gradientn(colors = pal, values=scales::rescale(c(0,5,seq(10,30,2))))