On 01-Nov-05 Erez wrote: > Hi > > I need an advise if any one can help me. > i have mass of data in 2 array A and B: > A = 0 1 0 0 1 1 0 0 > B = 0 0 0 1 0 1 1 1 > and i have 3 rules to merge them into 3rd array C: > if A[i] + B[i] == 0 then C[i]=0 > if A[i] + B[i] == 1 then C[i]=1 > if A[i] + B[i] == 2 then C[i]=2 > it looks easy but with the regular way (loop) with large data it takes > days (i test it). > If any one can advise me what to do i'll be happy. > > Thanks > Erez
Maybe there is a hidden complication in your context, but if those are the only possibilities (as you have stated it above), then what is wrong with: C = A + B ?? On the other hand, for instance, if C has values and you only want to change those values as above for the relevant values of i, then you could do ix <- (A+B==0)|(A+B==1)|(A+B==2) C[ix] <- A[ix] + B[ix] or some similar possibility, depending on what you really want to do. Best wishes, Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <[EMAIL PROTECTED]> Fax-to-email: +44 (0)870 094 0861 Date: 05-Nov-05 Time: 14:55:33 ------------------------------ XFMail ------------------------------ ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html