我想根据名为“数据集”的变量为添加到地图的点设置自定义形状、大小和颜色。如果我将所有点的形状设置为相同类型，我就可以设置点的颜色，但我希望有一张包含更多信息的地图。当我运行这段代码时，所有点都是黑色的圆圈。我缺少什么？
感谢大家的帮助和时间！
这是一个可重现的示例：
# Read in libraries
library(ggplot2)
library(maps)
library(maptools)
library(ggmap)
# Create mapping objects
world <- map_data("world2")
world$long <- world$long
state_dat <- map_data("state")
canada <- world[world$region==c("Canada"),]
map_dat <- rbind(state_dat, canada)
# Create custom shapes, sizes, colors
pt_colors=c("red", "blue", "grey", "green")
shapes = c(120, 22, 24, 21)
shape_size = c(1.1, 0.8, 1, 1)
# Create lat/long dataframe
xy <- data.frame(Dataset=c("GBIF","Flower","GBIF","Leaf","DNA","GBIF","GBIF","Leaf","GBIF","GBIF","DNA","GBIF","DNA","GBIF","GBIF","Leaf","GBIF","GBIF","GBIF","DNA"),
lat=c(38.89450,34.45300,39.86556,30.38818,28.74590,33.78527,41.23439,30.37935,41.38250,40.60648,30.87580,40.56425,28.75000,41.52666,35.46451,30.73621,38.50221,33.70335,38.98000,29.61100),
long=c(-77.06292,-84.22643,-79.50248,-84.64519,-81.47860,-84.37109,-81.46374,-86.17667,-72.10861,-74.53538,-84.41520,-74.86654,-81.47750,-73.15833,-78.89952,-86.73095,-78.40308,-86.70289,-77.03917,-81.78740)
)
# Create base map
p0 <- ggplot() +
geom_polygon(data=map_dat,aes(x=long,y=lat,group=group, fill=region),fill="white",color="black", show.legend=FALSE)+
coord_map("gilbert",xlim=c(-60,-97),ylim=c(15,47.5)) +#mollweide is pretty good
labs(x=expression("Longitude"*~degree*W), …我有一个现有的数组，我想命名这个数组的维度。我不能使用dimnames=of的参数，array()因为我需要用不同的函数制作这个数组。我需要使用类似于此的内容重命名维度names(my.array)<-my.names。
感谢您的帮助（如果您还不知道，我是新手）