我正忙于开发一个模块，该模块在 20x20m 单元大小的土壤样本数据上实现 autoKrige（自动地图库）。克里金法完成后，我想用字段边界裁剪/掩盖克里金法结果。
裁剪/遮罩的问题在于（由于 20x20 单元格）字段的边界会产生“阶梯”效果。我正在寻找的是一个平滑的边界（穿过细胞）。
下面是生成上述两种场景的代码：
library(sp)
library(rgeos)
#create polygon
r1 <- cbind(c(641777, 642290, 642276, 641794), c(7036885, 7036743, 7036154, 7036146))
r2 <- cbind(c(642320, 642478, 642494, 642314), c(7036732, 7036699, 7036296, 7036290))
sr1 <- Polygons(list(Polygon(r1)),"r1")
sr2 <- Polygons(list(Polygon(r2)),"r2")
boundary.sp <- SpatialPolygons(list(sr1,sr2))
boundary.sp@proj4string <- CRS('+proj=utm +zone=35 +south +datum=WGS84 +units=m +no_defs')
#create bounding box grid
bbox <- bbox(boundary.sp)
boundary.grid <- expand.grid(x = seq(from = bbox[1], to = bbox[3], by = 20), y = seq(from = bbox[2], to = bbox[4], by = 20))
coordinates(boundary.grid) <- ~x + y
gridded(boundary.grid) <- TRUE
boundary.grid@proj4string <- boundary.sp@proj4string
#create SpatialPixels grid
boundary.grid.stepped <- boundary.grid[!is.na(over(boundary.grid, boundary.sp)),]
plot(boundary.grid.stepped)
#cut grid with polygon to create SpatialPolygons grid
boundary.poly.grid <- as.SpatialPolygons.GridTopology(getGridTopology(boundary.grid), proj4string = CRS('+proj=utm +zone=35 +south +datum=WGS84 +units=m +no_defs'))
boundary.grid.smooth <- gIntersection(boundary.poly.grid, boundary.sp, byid=TRUE)
plot(boundary.grid.smooth)
目前，调用 autoKrige 时，上述网格 (boundary.grid.stepped) 作为“new_data”参数传递。
哪种方法更好，我该如何实施：
1) 事先准备好目标网格并将其用作“new_data”，或者，
2）在边界框网格上进行克里金法并在之后进行剪切/裁剪/蒙版？