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I have a dataset with points in NYC. I extract the bounding box (max and min lat/lon) and plot it on a map. It works for the basemap stamen watercolor, but not for google's. Why?

Here is the code to create the bounding box polygon:

library(ggmap)

bbx <- c(left=-74.06077,bottom=40.63317,right=-73.76324,top=40.84902)
x <- c(bbx["left"], bbx["left"], bbx["right"], bbx["right"])
y <- c(bbx["bottom"], bbx["top"], bbx["top"], bbx["bottom"])
df <- data.frame(x, y)

Here is the code to plot the bbox on the stamen+watercolor map, and it works:

myMap <-get_map(location=bbx,source="stamen",maptype="watercolor", crop=FALSE)
ggmap(myMap)+geom_polygon(aes(x=x, y=y), data=df, fill="red", alpha=.5)

correct map plot

Here is the code to plot the bbox on the google+satellite map, and it doesn't work:

myMap2 <-get_map(location=bbx,source="google",maptype="satellite")
ggmap(myMap2)+geom_polygon(aes(x=x, y=y), data=df, fill="red", alpha=.5)

incorrect map plot

1

You used an experimental function usage:

Warning: bounding box given to google - spatial extent only approximate.
converting bounding box to center/zoom specification. (experimental)

I recommend you to use get_googlemap function. Use center of location instead boundary box:

myMap2 <- get_googlemap(center = c(lon=mean(bbx[c(1,3)]), lat=mean(bbx[c(2,4)])),
                        zoom =11, maptype = "satellite")
ggmap(myMap2) + geom_polygon(aes(x=x, y=y), data=df, fill="red", alpha=.5)

enter image description here

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