在shapefile后面绘制栅格

Question

如何在shapefile对象后面绘制"栅格"对象？两者都可以自己绘制,但是这些点不会覆盖栅格:

require(rgdal)
require(maptools)
require(raster)

myproj = "+proj=utm +zone=12 +north +ellps=WGS84 +units=m"
shp = readShapeSpatial(fn.shp, proj4string = CRS(myproj))
ras = raster(fn.tif)

plot(ras)
plot(shp, bg="transparent", add=TRUE)

Answer 1

使用点,线和多边形过度绘制栅格图应该可以正常工作,如下例所示.

我最好的猜测是,Spatial*您尝试在栅格顶部绘制的对象落在绘制区域之外.您是否检查过两个raster和Spatial*对象是否在同一个CRS中,并且(假设它们)边界框重叠？(即尝试bbox(shp)并bbox(ras)比较结果).

library(rgdal)
library(raster)
# Create a raster
ras <- raster(ncols=36, nrows=18)
ras[] <- runif(ncell(ras))
# Create a SpatialPoints object
shpPts <- spsample(Spatial(bbox=bbox(ras)), 20, type="random")
# Create a SpatialPolygons object
p1 <- rbind(c(-10,0), c(140,60), c(160,0), c(140,-55), c(-10,0))
shpPolys <- SpatialPolygons( list(Polygons(list(Polygon(p1)), 1)))

# Plot them, one layer after another
plot(ras)
plot(shpPts, pch=16, col="red", add=TRUE)
plot(shpPolys, col="yellow", add=TRUE)