From: jim holtman <jholtman_at_gmail.com>

Date: Sun 21 Jan 2007 - 14:30:23 GMT

Date: Sun 21 Jan 2007 - 14:30:23 GMT

# create a matrix of all combination of bases 3,3,2
mat1 <- expand.grid(0:1, 0:2, 0:2)[,3:1]
base <- c(3,3,2) # define the bases

# now create the multiplier

mbase <- c(rev(cumprod(rev(base))),1)[-1]
# show the data

mat1

base

mbase

# combine with original

cbind(mat1, conv=colSums(apply(mat1, 1, function(x) x*mbase)))

On 1/21/07, Adrian Dusa <dusa.adrian@gmail.com> wrote:

*>
*

> Hi again,

*>
**> I was contemplating the solution using base 3:
**> set.seed(3)
**> mat2 <- matrix(sample(0:2, 15, replace=T), 5, 3)
**>
**> Extracting the line numbers is simple:
**> bases <- c(3, 3, 3)^(2:0) # or just 3^(2:0)
**> colSums(apply(mat2, 1, function(x) x*bases)) + 1
**> [1] 7 23 25 8 1
**>
**> The problem is sometimes the columns have different number of levels, as in:
**> mat1 <- expand.grid(0:2, 0:2, 0:1)[,3:1]
**>
**> Is there any chance to combine different bases in order to obtain the
**> corresponding line numbers?
**> I thought of something like:
**> bases <- c(3, 3, 2)^(2:0)
**>
**> but it doesn't work (sigh).
**>
**> Thanks for any hint,
**> Adrian
**>
**> --
**> Adrian Dusa
**> Romanian Social Data Archive
**> 1, Schitu Magureanu Bd
**> 050025 Bucharest sector 5
**> Romania
**> Tel./Fax: +40 21 3126618 \
**> +40 21 3120210 / int.101
**>
**> ______________________________________________
**> 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
**> and provide commented, minimal, self-contained, reproducible code.
**>
*

-- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve? ______________________________________________ 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 and provide commented, minimal, self-contained, reproducible code.Received on Mon Jan 22 01:35:26 2007

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