如何向量化 R 中的以下双 for 循环?
a <- seq(1,10, length=5)
b <- seq(0,1, length=4)
fun <- function(a,b){return(a+b)}
out <- matrix(NaN, nrow=5, ncol=4)
for(i in 1:5) {
for(j in 1:4) {
out[i, j] <- fun(a[i], b[j])
}
}
例如,我尝试过,但没有成功。请指教,提前谢谢
outer(1:nrow(out), 1:ncol(out), FUN = fun(a,b))
mapply(out, fun)