r语言 - Sum over spatialGridDataFrame: rowSums or colSums

Question

我想对空间格网数据框进行简单的操作。考虑我需要知道每个空间点(此处行(的每列的总和。不幸的是，我无法使用 sum 或 rowSums 函数来做到这一点。你能帮我怎么做吗？我搜索了很多，但真的没有看到任何类似的案例。

我的数据摘要是：

FLint
Object of class SpatialGridDataFrame
Object of class SpatialGrid
Grid topology:
cellcentre.offset cellsize cells.dim
x          582228.8 9.071439       568
y         4505538.0 9.071439       445
SpatialPoints:
x       y
[1,] 582228.8 4509566
[2,] 582237.9 4509566
....
Data summary:
Deterministic        sim001           sim002                   
Min.   :1        Min.   :1        Min.   :1               
1st Qu.:1        1st Qu.:1        1st Qu.:1             
Median :1        Median :1        Median :1               
Mean   :1        Mean   :1        Mean   :1               
3rd Qu.:1        3rd Qu.:1        3rd Qu.:1              
Max.   :1        Max.   :1        Max.   :1               
NA's   :220354   NA's   :220354   NA's   :220354   

在这里，我尝试了很多方法来总结例如最后一列中的两个：

y2 <- rowSums (FLint[,2:3], na.rm = TRUE, dims = 1)
Error in base::rowSums(x, na.rm = na.rm, dims = dims, ...) : 
'x' must be an array of at least two dimensions

Answer 1

我对你想要rowSums()还是colSums()有点困惑，但两者都将以相同的方式使用：

您需要通过 S4 对象的data槽调用rowSums()

这是一个玩具示例

library(sp)
## data taken from ?SpatialGridDataFrame
data(meuse.grid) # only the non-missing valued cells
coordinates(meuse.grid) = c("x", "y") # promote to SpatialPointsDataFrame
gridded(meuse.grid) <- TRUE # promote to SpatialPixelsDataFrame
x = as(meuse.grid, "SpatialGridDataFrame")
## the data is contained in '@data'
rowSums(x@data[, c("part.a", "part.b")], na.rm = T)

所以在你的例子中，我想你会想要

rowSums(Flint@data[, 2:3])

---

如果您查看结构，您可以看到数据的位置

str(x)
Formal class 'SpatialGridDataFrame' [package "sp"] with 4 slots
..@ data       :'data.frame': 8112 obs. of  5 variables:
.. ..$ part.a: num [1:8112] NA NA NA NA NA NA NA NA NA NA ...
.. ..$ part.b: num [1:8112] NA NA NA NA NA NA NA NA NA NA ...
.. ..$ dist  : num [1:8112] NA NA NA NA NA NA NA NA NA NA ...
.. ..$ soil  : Factor w/ 3 levels "1","2","3": NA NA NA NA NA NA NA NA NA NA ...
.. ..$ ffreq : Factor w/ 3 levels "1","2","3": NA NA NA NA NA NA NA NA NA NA ...
..@ grid       :Formal class 'GridTopology' [package "sp"] with 3 slots
.. .. ..@ cellcentre.offset: Named num [1:2] 178460 329620
.. .. .. ..- attr(*, "names")= chr [1:2] "x" "y"
.. .. ..@ cellsize         : Named num [1:2] 40 40
.. .. .. ..- attr(*, "names")= chr [1:2] "x" "y"
.. .. ..@ cells.dim        : Named int [1:2] 78 104
.. .. .. ..- attr(*, "names")= chr [1:2] "x" "y"
..@ bbox       : num [1:2, 1:2] 178440 329600 181560 333760
.. ..- attr(*, "dimnames")=List of 2
.. .. ..$ : chr [1:2] "x" "y"
.. .. ..$ : chr [1:2] "min" "max"
..@ proj4string:Formal class 'CRS' [package "sp"] with 1 slot
.. .. ..@ projargs: chr NA