93 lines
2.5 KiB
R
93 lines
2.5 KiB
R
|
## ----loadLibs, echo=FALSE, results="hide"-------------------------------------
|
||
|
|
library(foreach)
|
||
|
|
registerDoSEQ()
|
||
|
|
|
||
|
|
## ----init1,echo=FALSE,results="hide"------------------------------------------
|
||
|
|
sim <- function(a, b) 10 * a + b
|
||
|
|
avec <- 1:2
|
||
|
|
bvec <- 1:4
|
||
|
|
|
||
|
|
## ----for1---------------------------------------------------------------------
|
||
|
|
x <- matrix(0, length(avec), length(bvec))
|
||
|
|
for (j in 1:length(bvec)) {
|
||
|
|
for (i in 1:length(avec)) {
|
||
|
|
x[i,j] <- sim(avec[i], bvec[j])
|
||
|
|
}
|
||
|
|
}
|
||
|
|
x
|
||
|
|
|
||
|
|
## ----foreach1-----------------------------------------------------------------
|
||
|
|
x <-
|
||
|
|
foreach(b=bvec, .combine='cbind') %:%
|
||
|
|
foreach(a=avec, .combine='c') %do% {
|
||
|
|
sim(a, b)
|
||
|
|
}
|
||
|
|
x
|
||
|
|
|
||
|
|
## ----foreach2-----------------------------------------------------------------
|
||
|
|
x <-
|
||
|
|
foreach(b=bvec, .combine='cbind') %:%
|
||
|
|
foreach(a=avec, .combine='c') %dopar% {
|
||
|
|
sim(a, b)
|
||
|
|
}
|
||
|
|
x
|
||
|
|
|
||
|
|
## ----foreach3-----------------------------------------------------------------
|
||
|
|
opts <- list(chunkSize=2)
|
||
|
|
x <-
|
||
|
|
foreach(b=bvec, .combine='cbind', .options.nws=opts) %:%
|
||
|
|
foreach(a=avec, .combine='c') %dopar% {
|
||
|
|
sim(a, b)
|
||
|
|
}
|
||
|
|
x
|
||
|
|
|
||
|
|
## ----init2, echo=FALSE, results="hide"----------------------------------------
|
||
|
|
sim <- function(a, b) {
|
||
|
|
x <- 10 * a + b
|
||
|
|
err <- abs(a - b)
|
||
|
|
list(x=x, err=err)
|
||
|
|
}
|
||
|
|
|
||
|
|
## ----for2---------------------------------------------------------------------
|
||
|
|
n <- length(bvec)
|
||
|
|
d <- data.frame(x=numeric(n), a=numeric(n), b=numeric(n), err=numeric(n))
|
||
|
|
|
||
|
|
for (j in 1:n) {
|
||
|
|
err <- Inf
|
||
|
|
best <- NULL
|
||
|
|
for (i in 1:length(avec)) {
|
||
|
|
obj <- sim(avec[i], bvec[j])
|
||
|
|
if (obj$err < err) {
|
||
|
|
err <- obj$err
|
||
|
|
best <- data.frame(x=obj$x, a=avec[i], b=bvec[j], err=obj$err)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
d[j,] <- best
|
||
|
|
}
|
||
|
|
d
|
||
|
|
|
||
|
|
## ----innercombine-------------------------------------------------------------
|
||
|
|
comb <- function(d1, d2) if (d1$err < d2$err) d1 else d2
|
||
|
|
|
||
|
|
## ----foreach4-----------------------------------------------------------------
|
||
|
|
opts <- list(chunkSize=2)
|
||
|
|
d <-
|
||
|
|
foreach(b=bvec, .combine='rbind', .options.nws=opts) %:%
|
||
|
|
foreach(a=avec, .combine='comb', .inorder=FALSE) %dopar% {
|
||
|
|
obj <- sim(a, b)
|
||
|
|
data.frame(x=obj$x, a=a, b=b, err=obj$err)
|
||
|
|
}
|
||
|
|
d
|
||
|
|
|
||
|
|
## ----foreach5-----------------------------------------------------------------
|
||
|
|
library(iterators)
|
||
|
|
opts <- list(chunkSize=2)
|
||
|
|
d <-
|
||
|
|
foreach(b=bvec, j=icount(), .combine='rbind', .options.nws=opts) %:%
|
||
|
|
foreach(a=avec, i=icount(), .combine='comb', .inorder=FALSE) %dopar% {
|
||
|
|
obj <- sim(a, b)
|
||
|
|
data.frame(x=obj$x, i=i, j=j, err=obj$err)
|
||
|
|
}
|
||
|
|
d
|
||
|
|
|