Hey, I think I have a solution for your problem: Correl<-apply(DataArray_1,1:3, function(d1) apply(DataArray_2,c(2,1,3), function(d) cor(d1,d)) ) Correl<-Correl[1:4,,,] dimnames(Correl)[[1]]<-c Correl<-aperm(Correl,c(2,3,1,4))
This one should work. :-) Best Regards, Christian Sauvik De schrieb: > Hi there, > > Thanks again for your reply. I know for-loop is always a solution to > my problem and I had already coded using for-loop. But the number of > levels for each dimension is large enough in actual problem and hence > it was time-consuming. > So, I was just wondering if there are any other alternative way-outs > to solving my problem. That's why I tried with apply functions > (sapply)assuming that this might work out faster even fractionally as > compared to for-loop. > > Cheers, > Sauvik > > On Mon, Jul 27, 2009 at 12:28 AM, Poersching <poerschin...@web.de > <mailto:poerschin...@web.de>> wrote: > > Sauvik De schrieb: >> Hi: >> Lots of thanks for your valuable time! >> >> But I am not sure how you would like to use the function in this >> situation. >> >> As I had mentioned that the first element of my output array >> should be like: >> >> >> cor(DataArray_1[dimnames(Correl)[[1]][1],dimnames(Correl)[[2]][1],dimnames(Correl)[[4]][1],],DataArray_2[dimnames(Correl)[[1]][1],dimnames(Correl)[[3]][1],dimnames(Correl)[[4]][1],],use="pairwise.complete.obs") >> >> in my below code. >> >> and >> >> the output array of correlation I wish to get using "sapply" as >> follows: >> >> Correl = sapply(Correl,function(d) >> cor(DataArray_1[...],DataArray_2[...], >> use="pairwise.complete.obs")) >> >> So it would be of great help if you could kindly specify how to >> utilise your function "findIndex" in ... >> >> Apologies for all this! >> >> Thanks & Regards, >> Sauvik >> > Hey, > sorry, I haven't understood your problem last time, but now this > solution should solve your problem, so I hope. :-) > It's only a for to loop, but an apply function may work too. I > will think about this, but for now... ;-) > > la<-length(a) > lb<-length(b) > lc<-length(c) > ld<-length(d) > for (ia in 1:la) { > for (ib in 1:lb) { > for (ic in 1:lc) { > for (id in 1:ld) { > Correl[ia,ib,ic,id]<-cor( > DataArray_1[dimnames(Correl)[[1]][ia], > dimnames(Correl)[[2]][ib], > dimnames(Correl)[[4]][id],] > , > DataArray_2[dimnames(Correl)[[1]][ia], > dimnames(Correl)[[3]][ic], > dimnames(Correl)[[4]][id],] > , > use="pairwise.complete.obs") > } > } > } > } > ## with function findIndex you can find the dimensions with > ## i.e. cor values greater 0.5 or smaller -0.5, like: > findIndex(Correl,Correl[Correl>0.5]) > findIndex(Correl,Correl[Correl<(-0.5)]) > > I have changed the code of the function findIndex in line which > contents: el[j]<-which(is.element(data,element[j])) > > Rigards, > Christian > >> >> On Sun, Jul 26, 2009 at 3:54 PM, Poersching<poerschin...@web.de >> <mailto:poerschin...@web.de>> wrote: >> > Sauvik De schrieb: >> > >> > Hi Gabor: >> > Many thanks for your prompt reply! >> > The code is fine. But I need it in more general form as I had >> mentioned that >> > I need to input any 0 to find its dimension-names. >> > >> > Actually, I was using "sapply" to calculate correlation and >> this idea was >> > required in the middle of correlation calculation. >> > I am providing the way I tried my calculation. >> > >> > a= c("A1","A2","A3","A4","A5") >> > b= c("B1","B2","B3") >> > c= c("C1","C2","C3","C4") >> > d= c("D1","D2") >> > e= c("E1","E2","E3","E4","E5","E6","E7","E8") >> > >> > DataArray_1 = array(c(rnorm(240)),dim=c(length(a),length(b), >> > length(d),length(e)),dimnames=list(a,b,d,e)) >> > DataArray_2 = array(c(rnorm(320)), dim=c(length(a),length(c), >> > length(d),length(e)),dimnames=list(a,c,d,e)) >> > >> > #Defining an empty array which will contain the correlation >> values (output >> > array) >> > Correl = array(NA, dim=c(length(a),length(b), >> > length(c),length(d)),dimnames=list(a,b,c,d)) >> > >> > #Calculating Correlation between attributes b & c over values of e >> > Correl = sapply(Correl,function(d) >> cor(DataArray_1[...],DataArray_2[...], >> > use="pairwise.complete.obs")) >> > >> > This is where I get stuck. >> > In the above, d is acting as an element in the "Correl" array. >> Hence I need >> > to get the dimension-names for d. >> > >> > #The first element of Correl will be: >> > >> >> cor(DataArray_1[dimnames(Correl)[[1]][1],dimnames(Correl)[[2]][1],dimnames(Correl)[[4]][1],],DataArray_2[dimnames(Correl)[[1]][1],dimnames(Correl)[[3]][1],dimnames(Correl)[[4]][1],],use="pairwise.complete.obs") >> > >> > So my problem boils down to extracting the dim-names in terms >> of element(d) >> > and not in terms of Correl (that I have mentioned as "..." in >> the above >> > code) >> > >> > My sincere thanks for your valuable time & suggestions. >> > >> > Many Thanks & Kind Regards, >> > Sauvik >> > >> > >> > On Sun, Jul 26, 2009 at 5:26 AM, Gabor Grothendieck >> <ggrothendi...@gmail.com <mailto:ggrothendi...@gmail.com> >> > >> > >> > wrote: >> > >> > >> > >> > >> > Try this: >> > >> > >> > >> > ix <- c(1, 3, 4, 2) >> > mapply("[", dimnames(mydatastructure), ix) >> > >> > >> > [1] "S1" "T3" "U4" "V2" >> > >> > >> > On Sat, Jul 25, 2009 at 5:12 PM, Sauvik >> De<sauvik.s...@gmail.com <mailto:sauvik.s...@gmail.com>> wrote: >> > >> > >> > Hi: >> > How can I extract the dimension-names of a pre-defined element in a >> > multidimensional array in R ? >> > >> > A toy example is provided below: >> > I have a 4-dimensional array with each dimension having certain >> length. >> > >> > >> > In >> > >> > >> > the below example, "mydatastructure" explains the structure of >> my data. >> > >> > mydatastructure = array(0, >> > >> > >> > dim=c(length(b),length(z),length(x),length(d)), >> > >> > >> > dimnames=list(b,z,x,d)) >> > >> > where, >> > b=c("S1","S2","S3","S4","S5") >> > z=c("T1","T2", "T3") >> > x=c("U1","U2","U3","U4") >> > d=c("V1","V2") >> > >> > Clearly, "mydatastructure" contains many 0's. >> > Now how can I get the dimension-names of any particular 0 ? >> > That is, my input should be a particular 0 in the array >> "mydatastructure" >> > (Suppose this 0 corresponds to S1,T3,U4 & V2 in the array). Then my >> > >> > >> > output >> > >> > >> > should be S1,T3,U4 & V2. >> > >> > The function "dimnames" didn't help me with the solution. >> > Any idea will greatly be appreciated. >> > >> > Thanks for your time! >> > >> > Kind Regards, >> > Sauvik >> > >> > [[alternative HTML version deleted]] >> > >> > ______________________________________________ >> > R-help@r-project.org <mailto:R-help@r-project.org> mailing list >> > https://stat.ethz.ch/mailman/listinfo/r-help >> > PLEASE do read the posting guide >> > >> > >> > http://www.R-project.org/posting-guide.html >> > >> > >> > and provide commented, minimal, self-contained, reproducible code. >> > >> > >> > >> > [[alternative HTML version deleted]] >> > >> > ______________________________________________ >> > R-help@r-project.org <mailto:R-help@r-project.org> mailing list >> > https://stat.ethz.ch/mailman/listinfo/r-help >> > PLEASE do read the posting guide >> http://www.R-project.org/posting-guide.html >> > and provide commented, minimal, self-contained, reproducible code. >> > >> > >> > >> > Hey, >> > >> > I have spend some time to write a function, which should >> fulfill your needs. >> > so i hope ;-) >> > >> > findIndex<-function(data,element) { >> > ld<-length(data) >> > el<-which(is.element(data,element)) >> > lel<-length(el) >> > ndim<-length(dim(data)) >> > ind<-array(,dim=c(lel,ndim),dimnames=list(el,1:ndim)) >> > precomma<-"" >> > tempdata<-data >> > tempel<-el >> > for (j in 1:lel) { >> > data<-tempdata >> > el<-tempel >> > ld<-length(data) >> > for (i in ndim:1) { >> > ratio<-el[j]/(ld/dim(data)[i]) >> > if (ratio-trunc(ratio)>0) { >> > ind[j,i]<-trunc(ratio)+1 >> > } else { >> > ind[j,i]<-trunc(ratio) >> > } >> > if (length(dim(data))>1) { >> > k<-1 >> > while (k>=1 & k<=(i-1)) { >> > precomma<-paste(precomma,",",sep="") >> > k<-k+1 >> > } >> > >> > >> >> data<-as.array(eval(parse(text=paste("data[",precomma,ind[j,i],"]",sep="")))) >> > precomma<-"" >> > ld<-length(data) >> > el[j]<-which(is.element(data,element[j])) >> >> > } >> > } >> > } >> > return(ind) >> > } >> > >> > Regards, >> > Christian Porsche >> > >> > > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
