gstat 包未返回 NA

发布于 2025-01-10 02:27:29 字数 988 浏览 1 评论 0原文

我正在使用 gstat 软件包估计未知地点之一的降雨量。
我只是测试这些代码，以表明即使不满足“nmin”、nmax 和“maxdist”参数，“gstat”包也会返回估计值。代码应返回“NA”。
我有三个相邻站点，距离兴趣点位置分别为 97.51、37.45 和 50.94 公里。您有什么建议吗？

library(gstat)
library(sp)

Rainfall = data.frame(x = c(-47.6, -48.9, -48.2, -48.9, -47.6, -48.6), 
                      y = c(-23.4, -24.0, -23.9, -23.1, -22.7, -22.5), 
                      Rain = c(27.0,  33.4,  34.6,  18.2,   30.8, 42.8))

sp = Rainfall
coordinates(sp) = ~x+y
xi = c(-48.0530600)
yi = c(-23.5916700)
grid = expand.grid (xi=xi ,yi=yi)
coordinates(grid) = ~xi + yi

idw(sp$Rain~1, sp, grid, nmin=2,nmax=3, maxdist=25)

[inverse distance weighted interpolation]
class       : SpatialPointsDataFrame 
features    : 1 
extent      : -48.05306, -48.05306, -23.59167, -23.59167  (xmin, xmax, ymin, ymax)
crs         : NA 
variables   : 2
names       :        var1.pred, var1.var 
value       : 32.2319969930987,       NA

原文

I'm estimating the value of rainfall in one of the unknown locations with the gstat package.
I'm merely testing these codes to show that the 'gstat' package returns an estimated value even when the 'nmin' nmax and'maxdist' parameters aren't met. The codes should return 'NA'.
I have three neighbouring stations that are 97.51, 37.45, and 50.94 kilometres from the location of the point of interest. Do you have any recommendations?

library(gstat)
library(sp)

Rainfall = data.frame(x = c(-47.6, -48.9, -48.2, -48.9, -47.6, -48.6), 
                      y = c(-23.4, -24.0, -23.9, -23.1, -22.7, -22.5), 
                      Rain = c(27.0,  33.4,  34.6,  18.2,   30.8, 42.8))

sp = Rainfall
coordinates(sp) = ~x+y
xi = c(-48.0530600)
yi = c(-23.5916700)
grid = expand.grid (xi=xi ,yi=yi)
coordinates(grid) = ~xi + yi

idw(sp$Rain~1, sp, grid, nmin=2,nmax=3, maxdist=25)

[inverse distance weighted interpolation]
class       : SpatialPointsDataFrame 
features    : 1 
extent      : -48.05306, -48.05306, -23.59167, -23.59167  (xmin, xmax, ymin, ymax)
crs         : NA 
variables   : 2
names       :        var1.pred, var1.var 
value       : 32.2319969930987,       NA

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