Dear List,

I have got error message when I run the R-code. Can anyone has a suggestion?



v.code <- df.bm7[,c(10:31)]; v.code[1:3,]
names(v.code)
CM = v.code # variable binomial code
sim.sp <- function(data,CM,n,N)
{
  C <- matrix(rep(NA,N),ncol=1)
    for(i in 1:N)
    {
        j <- n
        xx <- which(colSums(CM[j,])==1)
        V <- names(xx)
        V <- paste(V, collapse="+")
        V <- paste("SBA~", V)
        rd <- round(nrow(data)*(2/3))
        d <- sample(seq(1:nrow(data)),rd)
        dat1 <- data[d,]
        dat2 <- data[-d,]
        crd <- cbind(dat1$Longitude,dat1$Latitude)
        dist60 <- dnearneigh(crd,0,60,longlat=F)
        dist60sw <- nb2listw(dist60, style="B")
        fm <- errorsarlm(as.formula(V), data=dat1, listw=dist60sw)
        pred <- predict(fm,dat2)
        C[i,1] <- cor(dat2$SBA,pred)
        out <- cbind(C)
    }
    colMeans(out)
}

sim.sp(df2007.5k.s2,CM,1,1000)
Error in nb2listw(dist60, style = "B") : Empty neighbour sets found

And, here are my partial data and addition information just in case.

> df2007.5k.s2[1:5,]
    Longitude Latitude Ring stage2       SBA     corn      sbn    w.wit
oats      afl      dbn   vg.frt    fidle grs.pstr    wdlnd  nlcd.ow nlcd.dec
821  419.9678 496.3359 5000      2 0.2041200 6.873500 6.515908 5.861865
5.139832 6.260552 5.087444 0.000000 4.818602 6.897949 4.927745 7.073408
7.348551
822  440.9583 533.2685 5000      2 1.1832698 6.829823 6.402711 4.098471
5.660730 6.394553 4.700505 0.000000 4.399483 6.885719 5.159137 5.779678
7.617312
823  434.2998 550.4301 5000      2 0.8419848 6.901722 6.377190 4.575569
5.571924 6.411776 4.450634 3.496515 4.537781 6.874229 5.001530 6.249959
7.497547
824  388.2020 550.3011 5000      2 0.5563025 7.116200 6.467652 3.973543
4.894322 6.279565 5.872954 5.460165 3.973543 6.985068 4.958779 6.431883
7.524418
825  365.8802 548.6984 5000      2 0.5314789 7.236186 6.739166 5.571924
5.729373 6.810875 6.049045 4.537781 3.973543 6.921747 5.335227 5.892576
7.425795
    nlcd.shrb nlcd.grshrb   forest o.legume    devel  wetland   grains
ra.SDI
821  5.504978    6.599838 6.661026 4.450634 6.974943 6.640015 4.838805
25.94976
822  5.758828    5.736926 5.027859 5.064582 6.652622 7.020253 3.973543
25.62106
823  5.840769    5.937286 5.399468 4.274550 6.959373 7.125071 4.496390
27.71064
824  5.571924    6.287365 6.217362 3.496515 6.860364 6.366780 4.098471
26.62635
825  5.593287    6.247655 5.642505 3.973543 6.816315 6.278132 5.014894
28.65973
> v.code[1:5,]
    Latitude Longitude corn sbn afl grs.pstr nlcd.dec nlcd.grshrb devel
wetland ra.SDI oats nlcd.shrb w.wit wdlnd nlcd.ow dbn vg.frt fidle forest
169        0         1    0   0   0        0        0           0
0       0      0    1         1     0     0       0   0      0     0      0
170        0         1    0   0   0        1        0           0
0       0      0    1         1     0     0       0   0      0     0      0
171        0         1    0   0   0        0        0           0
0       0      0    1         1     0     0       0   1      0     0      0
193        0         1    0   0   0        0        0           0
0       0      0    1         1     0     0       0   0      0     0      0
217        0         1    0   0   0        0        0           0
0       0      0    1         1     0     0       0   0      0     0      0
    o.legume grains
169        0      1
170        0      1
171        1      1
193        0      0
217        0      0

Thank you in advance!!

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