[R] , Updating Table

[Charles C. Berry]

On Fri, 23 Jul 2010, Marcus Liu wrote:

> Hi everyone,
>
> Is there any command for updating table withing a loop? 

 	"Loops? We don't need no stinking loops!"
 	 (From 'The Good, the Bad, and the Rgly')

tab <- table(data.raw, findInterval(seq(along=data.raw), ind+1 ) )
tab %*% upper.tri(tab,diag=T)

or

tab2 <- tapply( factor(data.raw), findInterval(seq(along=data.raw), ind+1 ), table)
Reduce( "+", tab2, accum=TRUE )

HTH,

Chuck

p.s. See the posting guide re including a reproducible example with 
requests like yours.

> For instance, at i, I have a table as ZZ = table(data.raw[1:ind[i]]) 
> where "ind" = c(10, 20, 30, ...). Then , ZZ will be as follow
>
> "A" "B" "C"
>  3    10   2
>
> At (i + 1), ZZ = table(data.raw[(ind[i]+1):ind[i+1]])
>
> "A" "B" "D"
>  4    7    8
>
> Is there any command that can update the table ZZ for each time so that in the above example, ZZ will be
>
> "A" "B" "C" "D"
>  7    17   2    8
>
> Thanks.
>
> liu
>
>
>
>
> 	[[alternative HTML version deleted]]
>
>

Charles C. Berry                            (858) 534-2098
                                             Dept of Family/Preventive Medicine
E mailto:cberry at tajo.ucsd.edu	            UC San Diego
http://famprevmed.ucsd.edu/faculty/cberry/  La Jolla, San Diego 92093-0901