R 3.2.1，在地图上反转颜色

Question

这是R代码的一部分

# create a new grouping variable
Percent_SEP12_Assets <- ifelse(sep[,8] <= 33, "Lower Third", ifelse(sep[,8] >= 55, "Upper Third", "Middle Third"))

# get the map
bbox <- make_bbox(sep$Longitude, sep$Latitude, f = 0.3)
map <- get_map(bbox)


# plot the map and use the grouping variable for the fill inside the aes
ggmap(map) +
  geom_point(data=sep, aes(x = Longitude, y = Latitude, color=Percent_SEP12_Assets ), size=5, alpha=0.6) +
  scale_color_manual(breaks=c("Upper Third", "Middle Third","Lower Third"), values=c("green","orange","red"))

但不是制作地图

“上三分之一”对应绿色 “中三”对应Orange “下三”对应红色

配色方案混淆了，即上三分之一对应红色，下三分之一对应绿色。

数字越大 = 好 = 绿色，但地图显示相反。如何解决这个问题？

到目前为止我尝试了什么

以下代码

# create a new grouping variable
Percent_SEP12_Assets <- ifelse(sep[,8] <= 33, "Lower Third", ifelse(sep[,8] >= 55, "Upper Third", "Middle Third"))
Percent_SEP12_Assets <- factor(Percent_SEP12_Assets)
levels(Percent_SEP12_Assets) <- c("Upper Third", "Middle Third", "Lower Third")


# get the map
bbox <- make_bbox(sep$Longitude, sep$Latitude, f = 0.3)
map <- get_map(bbox)


# plot the map and use the grouping variable for the fill inside the aes
ggmap(map) +
  geom_point(data=sep, aes(x = Longitude, y = Latitude, color=Percent_SEP12_Assets ), size=9, alpha=0.6) +
  scale_color_manual(values=c("green","orange","red"))

会给出这个，它会更正数据标签，但地图中的点是倒置的，即绿色的地方是红色的，反之亦然（蓝色圆圈中的点应该是红色的）

但是当我在原始代码中颠倒“红色”和“绿色”时，它可以工作（蓝色圆圈中的区域应该是红色的），但我相信这是一种“创可贴”的方法

# create a new grouping variable
Percent_SEP12_Assets <- ifelse(sep[,8] <= 33, "Lower Third", ifelse(sep[,8] >= 55, "Upper Third", "Middle Third"))

# get the map
bbox <- make_bbox(sep$Longitude, sep$Latitude, f = 0.3)
map <- get_map(bbox)


# plot the map and use the grouping variable for the fill inside the aes
ggmap(map) +
  geom_point(data=sep, aes(x = Longitude, y = Latitude, color=Percent_SEP12_Assets ), size=9, alpha=0.6) +
  scale_color_manual(breaks=c("Upper Third", "Middle Third","Lower Third"), values=c("red","orange","green"))

Answer 1

将Percent_SEP12_Assets转为因子变量并指定级别的顺序：

# create a new grouping variable
Percent_SEP12_Assets <- ifelse(sep[,8] <= 33, "Lower Third", ifelse(sep[,8] >= 55, "Upper Third", "Middle Third"))
Percent_SEP12_Assets <- factor(Percent_SEP12_Assets,
                               levels = c("Upper Third", "Middle Third", "Lower Third"))


# get the map
bbox <- make_bbox(sep$Longitude, sep$Latitude, f = 0.3)
map <- get_map(bbox)


# plot the map and use the grouping variable for the fill inside the aes
ggmap(map) +
  geom_point(data=sep, aes(x = Longitude, y = Latitude, color=Percent_SEP12_Assets ), size=5, alpha=0.6) +
  scale_color_manual(values=c("green","orange","red"))