将XY点添加到由levelplot生成的栅格地图中 [英] Add XY points to raster map generated by levelplot

问题描述

我有raster地图，这些地图是使用R中的raster程序包生成的.可以使用rasterVis程序包的levelplot函数将这些栅格图层可视化:

I have raster maps which are generated using the raster package in R. These raster layers can be visualized using the rasterVis package's levelplot function:

levelplot(rasterstack, layout=c(1, 2), 
          col.regions=colorRampPalette(c('darkred', 'red3', 'orange2', 'orange', 
                                         'yellow', 'lightskyblue', 'steelblue3', 
                                         'royalblue3', 'darkblue')))

现在，我想将xy坐标定义的一些z值添加到水平图映射中.包含z值的数据框有4列.第1列和第2列2包含x& y坐标，第3列包含layout(1，1)中地图1的z值，而layout(1，2)中列4的z值.

Now, I would like to add some z values defined by xy cordinates to the levelplot map. The dataframe containing z values has 4 columns. Columns 1 & 2 contain x & y coordinates, column 3 contains z values for map 1 in layout(1, 1) and column 4 for layout(1, 2).

每张地图的点数应相加，如果z< 0.05，pch=2，如果z> 0.05，pch=3.

The points per map should be added such that if z < 0.05, pch=2 and if z > 0.05, pch=3.

我已经在网上搜索并找到了Ripley的解决方案，但在我的情况下它不起作用:

I have searched the web and found a solution by Ripley but it does not work in my case:

levelplot(rcp852, xlab = "", ylab = "",
          panel = function(x, y, subscripts, ...) {
            panel.levelplot(x, y, subscripts, ...)
            panel.xyplot(topo$x,topo$y, cex = 0.5, col = 1)
          }
)

我尝试了许多其他选择，但是这些点与通过levelplot生成的地图不对齐.

I tried many other options but the points do not align with the map generated via levelplot.

推荐答案

layer对此非常方便:

s <- stack(replicate(2, raster(matrix(runif(100), 10))))
xy <- data.frame(coordinates(sampleRandom(s, 10, sp=TRUE)),
                z1=runif(10), z2=runif(10))

levelplot(s, margin=FALSE, at=seq(0, 1, 0.05)) + 
  layer(sp.points(xy, pch=ifelse(pts$z1 < 0.5, 2, 3), cex=2, col=1), columns=1) +
  layer(sp.points(xy, pch=ifelse(pts$z2 < 0.5, 2, 3), cex=2, col=1), columns=2)

请注意，layer的columns参数(也存在rows)指定要将图层添加到的面板.

Note that the columns argument to layer (rows also exists) specifies which panel(s) you want to add the layer to.

这篇关于将XY点添加到由levelplot生成的栅格地图中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！