inst/unitTests/runittwExtractDim.R

In twMisc: Utility functions of tw

test.one <- function(){
    A0 <- matrix(1:8,ncol=2) 
    A <- abind::abind( lapply(1:4, function(i){(i)*10+A0}), rev.along=0 )
    A3 <- abind::abind( lapply(1:3, function(i){(i)*100+A}), rev.along=0 )
    (res <- twExtractDim(A,2) ); 
    checkEquals( A[,,2], res, check.attributes = FALSE )
    #mtrace(twExtractDim)
    (res <- twExtractDim(A,2,iDim=2) )
    checkEquals( A[,2,], res , check.attributes = FALSE)
    (res <- twExtractDim(A3,2,iDim=2) )
    checkEquals( A3[,2,,], res , check.attributes = FALSE)
    (res <- twExtractDim(A3,2,iDim=3) )
    checkEquals( A3[,,2,], res, check.attributes = FALSE )
    
    resl <- twListArrDim(A)
    #str(resl)
    checkEquals(4, length(resl) )
    checkEquals( A[,,3], resl[[3]], check.attributes = FALSE)
    checkEquals( A[,,4], resl[[4]], check.attributes = FALSE)
    
    resl <- twListArrDim(A,2)
    #str(resl)
    checkEquals(2, length(resl) )
    checkEquals( A[,1,], resl[[1]], check.attributes = FALSE)
    checkEquals( A[,2,], resl[[2]], check.attributes = FALSE)
}

ztest.extractLastDims <- function(){
    # example of extracting from a matrix 
    (A <- matrix(1:6, ncol=2))
    (Aext <- abind::abind( lapply(1:4, function(i){(i)/10+A}), along=0 ))
    # Note that the second and third dimension of Aext correspond to A 
    
    # Now we whish to extract from Aext based on 
    # a criterion for the second and third dimension 
    (B <- diag(3)[,1:2])
    i <- which(B != 0)
    (A[i])
    # how to index Aext to obtain those indices?
    resExp <- matrix(0,nrow=nrow(Aext),ncol=length(i) )
    for( ii in seq(along.with=i) )
        resExp[,ii] <- Aext[,(i[ii]-1) %% 3+1,(i[ii]-1) %/% 3+1]
    (res <- twExtractFromLastDims(Aext,i))
    checkEquals( resExp, structure(res, dimnames=NULL) )
}