かなり前に、補間関数の定義に手をつけたことがないことを除いて、私は同様のおもちゃを書きました。もありraster::disaggregate
ます。
zexpand<-function(inarray, fact=2, interp=FALSE, ...) {
# do same analysis of fact to allow one or two values, fact >=1 required, etc.
fact<-as.integer(round(fact))
switch(as.character(length(fact)),
'1' = xfact<-yfact<-fact,
'2'= {xfact<-fact[1]; yfact<-fact[2]},
{xfact<-fact[1]; yfact<-fact[2];warning(' fact is too long. First two values used.')})
if (xfact < 1) { stop('fact[1] must be > 0') }
if (yfact < 1) { stop('fact[2] must be > 0') }
bigtmp <- matrix(rep(t(inarray), each=xfact), nrow(inarray), ncol(inarray)*xfact, byr=T) #does column expansion
bigx <- t(matrix(rep((bigtmp),each=yfact),ncol(bigtmp),nrow(bigtmp)*yfact,byr=T))
# the interpolation would go here. Or use interp.loess on output (won't
# handle complex data). Also, look at fields::Tps which probably does
# a much better job anyway. Just do separately on Re and Im data
return(invisible(bigx))
}