Map 中的标绘点不会因价格而异

Question

I plotted some data points on a map. The Map is the bounty King in Washington. I plotted them on the map successfully. My dataset consists of a column called prices. Their values range in between 0-800000. I created a new column, called MapColor to print the value either as red or blue based on the price value. If price> 400000 red, else blue.

Now when plotting the points in the map, if MapColor is red I need to map it as red points and if not black. This is how I tried it. But the colors are plotting black only. This is what I tried

long <- c(47.5112,47.7210   ,47.3684)
lat <- c(-122.257, -122.319, -122.031)
price <- c(287655,456355,662500,234563)

House <- data.frame(long, lat, price)
House$MapColor  <- ifelse(House$price >=400000, "red", "black")

col <- as.character(House$MapColor)

states <- map_data("state")

wa_df <- states %>%
  filter(region == "washington", subregion == 'king')



counties <- map_data("county")
wa_county <- counties %>%
  filter(region == "washington")

wa_base <-
  ggplot(data = wa_df,
         mapping = aes(x = long, y = lat, group = group)) +   geom_point(data = House,aes(x = long, y = lat),size = 0.5,inherit.aes = FALSE) +
  coord_fixed(1.3) +scale_color_manual(values=col)+
  geom_polygon(color = "black", fill = "gray")
#geom_point(data = House, mapping = aes(x = long, y = lat), color = "red")

wa_base + theme_nothing() +
  geom_polygon(data = wa_county, fill = NA, color = "black") +
  geom_polygon(color = "black", fill = NA)  # get the state border back on top

Answer 1

Please let me know if this is what you had in mind.

I think long and lat for those example points were reversed. I set the colors as either red or blue as per the description.

It maps the state polygon, then county, then adds the points using color = House$MapColor .

library(ggplot2)
library(ggmap)

lat <- c(47.5112, 47.7210, 47.3684)
long <- c(-122.257, -122.319, -122.031)
price <- c(287655, 456355, 662500)

House <- data.frame(long, lat, price)

House$MapColor <- ifelse(House$price >= 400000, "red", "blue")

wa_df <- map_data("state") %>%
  filter(region == "washington")

wa_county <- map_data("county") %>%
  filter(region == "washington")

ggplot(data = wa_df, mapping = aes(x = long, y = lat, group = group))+  
  geom_polygon(color = "black", fill = NA)+
  geom_polygon(data = wa_county, fill = NA, color = "black")+
  geom_point(data = House, mapping = aes(x = long, y = lat), color = House$MapColor)+
  coord_fixed(1.3)+
  theme_nothing()