nnmiss {SeqKnn} | R Documentation |
A function to select k nearest neighbors using Euclidean distance, and estimate missing value with weighted mean of selected neighbors.
nnmiss(x, xmiss, ismiss, K)
x |
data frame which contains only complete cases |
xmiss |
data frame which contains incomplete cases |
ismiss |
data frame with logical value(TRUE or FALSE) of xmiss |
K |
number of nearest neighbors |
Appropriate number of k is 10-20. However, we need to control k smaller in case missing rate is high, especially k is larger than the size of complete set.
## Not run: data(khan05) x <- as.matrix(khan05) N <- dim(x) p <- N[2] N <- N[1] nas <- is.na(drop(x %*% rep(1, p))) xcomplete <- x[!nas, ] ## complete set xbad <- x[nas, , drop = FALSE] ## incomplete set xnas <- is.na(xbad) xbadhat <- xbad xbadhat[1,]<-nnmiss(xcomplete, xbad[1,], xnas[1,], 10) ## End(Not run)