我尝试使用RANN包通过比较两个文件来提取最近的坐标点，然后将最近的提取点添加到另一个文件中。
我的文件->开火
lat lon frp
30.037 80.572 38.5
23.671 85.008 7.2
22.791 86.206 11.4
23.755 86.421 5.6
23.673 86.088 4.2
23.768 86.392 8.4
23.789 86.243 7.8
23.805 86.327 6.4
23.682 86.085 7.8
23.68 86.095 5.7
21.194 81.41 19
16.95 81.912 8
16.952 81.898 11.5
16.899 81.682 10.6
12.994 79.651 16.1
9.2 77.603 14.5
12.291 77.346 20.5
17.996 79.708 13.9
17.998 79.718 29.6
16.61 81.266 6.6
16.499 81.2 6.8
19.505 81.784 22.4
18.322 80.555 7.7
19.506 81.794 28.2
21.081 81.957 8.7
21.223 82.127 9.4
20.918 81.025 6.3
19.861 82.123 9.3
20.62 75.049 11.6
和第二个文件->风
lat lon si10 u10 v10
40 60 3.5927058834376 -0.874587879393667 -0.375465368327018
40 60.125 3.59519876134577 -0.836646189656238 -0.388624092937835
40 60.25 3.59769163925393 -0.798704499918809 -0.401782817548651
40 60.375 3.6001845171621 -0.76076281018138 -0.414941542159468
40 60.5 3.60246965524458 -0.722821120443951 -0.428380239634345
40 60.625 3.60496253315275 -0.684585309080651 -0.441538964245162
40 60.75 3.60766315088659 -0.646937740969094 -0.454977661720038
40 60.875 3.60911732966636 -0.609878416109279 -0.468976304923035
40 61 3.608701850015 -0.575172064256437 -0.484934758174451
40 61.125 3.60807863053795 -0.540759834029467 -0.500893211425867
40 61.25 3.60787089071227 -0.506053482176625 -0.516851664677283
40 61.375 3.60745541106091 -0.471641251949655 -0.533090090792759
40 61.5 3.60703993140955 -0.437229021722684 -0.548768571180115
40 61.625 3.60662445175819 -0.402522669869843 -0.565006997295591
40 61.75 3.60454705350139 -0.398993210359384 -0.579285613362648
40 61.875 3.60163869594186 -0.411346318645989 -0.592724310837524
40 62 3.59873033838234 -0.423405305306722 -0.606163008312401
40 62.125 3.59540650117145 -0.435758413593327 -0.619601705787278
40 62.25 3.59249814361192 -0.44781740025406 -0.633320376126214
40 62.375 3.5895897860524 -0.460170508540664 -0.646759073601091
40 62.5 3.58668142849287 -0.471935373575526 -0.660197771075968
40 62.625 3.57546347790613 -0.509288820061212 -0.666357174085286
40 62.75 3.56445326714507 -0.546642266546898 -0.672236604230545
40 62.875 3.55323531655832 -0.584289834658455 -0.678675980103923
40 63 3.54201736597158 -0.621643281144141 -0.684835383113241
40 63.125 3.53100715521052 -0.658996727629827 -0.69099478612256
40 63.25 3.51978920462378 -0.696350174115513 -0.697154189131878
40 63.375 3.50005392118414 -0.726644701580281 -0.692954596170979
40 63.5 3.46266075256166 -0.743115512629088 -0.668037011269646
我想将wind$si10 wind$u10 wind$v10添加到fire文件中，其最近的坐标对应于frp的值。首先，我只尝试使用变量si10，因为在RANN package和fire文件中，wind和si10文件应具有相同的列数。因此，我仅将代码与library(RANN)
read.table(file.choose(), sep="\t", header = T) -> wind_jan
read.table(file.choose(), sep="\t", header = T) -> fire_jan
names(fire_jan)
names(wind_jan)
closest <- RANN::nn2(data = wind_jan, query = fire_jan, k = 1)
closest
fire_jan$wind_lat <- wind_jan[closest$nn.idx, "lat"]
fire_jan$wind_lon <- wind_jan[closest$nn.idx, "lon"]
fire_jan$WS <- wind_jan[closest$nn.idx, "si10"]
一起使用
si10从以上代码中，我能够在fire$frp附近的坐标处提取u10值，但是当我对v10和wind变量中的变量应用相同的代码时{1}}文件，则无法在与si10相同的坐标上获取提取的值。
如何使用此代码解决此查询？
答案 0 :(得分：0)
您调用了不存在的closest_u $ nn.id。 读取wind df时，您的标签也许也会出错？
那是错误吗？