Permutation of dimensions, or generalized transpose.
Object to be transposed.
Integer vector giving the permutation.
Additional argument list.
a but with
permuted dimensions.as.data.frame or as.matrix. The order of the rows of the
data frame or matrix is left unchanged, and is determined by the
index slot of the object. Thus if a vector or matrix of
response, say Y, has its elements or rows aligned with the
design this property remains after the transposition, see
Examples. It must be kept in mind that this "design" order
can not be guessed when only the factors and their levels are known.aperm S3 method from the
base package.
myGDa <- Grid(nlevels = c("X" = 2, "Y" = 3, "Z" = 4))
myGDb <- aperm(myGDa, perm = c(3, 2, 1))
## evaluation of a function on the permuted array
myGD1 <- Grid(nlevels = c("X" = 2, "Y" = 3, "Z" = 4))
myPerm <- c(3, 2, 1)
myFun <- function(vec){ sin(vec["X"]) + vec["Y"] - vec["Z"]^2 }
## 'f1' contains the value of the function in the order of 'myGD1'
f1 <- apply_Grid(myGD1, fun = myFun)
## 'f2' contains the value of the function in the order of 'myGD2'
myGD2 <- aperm(myGD1, perm = myPerm)
f2 <- apply_Grid(myGD2, fun = myFun)
## note that 'as.matrix' sorts the observations in the index order
XYZ1 <- as.matrix(myGD1)
XYZ2 <- as.matrix(myGD2)
## check
f = apply(XYZ1, 1, myFun)
cbind(XYZ1, f1 = f1, XYZ2, f2 = f2, f = f)
eps <- sqrt(.Machine$double.eps)
all(abs(f1 - f) < eps) ## should be TRUE
all(abs(f2 - f) < eps) ## should be TRUE