On Tuesday, March 04, 2008 9:37, jose Bartolomei wrote:
> ...It is possible to manipulate or use the
> crosstabs (ct) result values as separate
> entities (eg., a<- first row, last column)?
If by "result values" you mean the counts of each category the
crosstabs function returns an array of counts (among other
things, e.g., attributes containing the marginals) that can be
accessed by index. If all you want is the counts, you can
use table():
> attach ( solder [ solder $ skips > 10 , ] )
> xt <- table ( Solder , Opening )
> detach()
> xt
S M L
Thin 99 15 9
Thick 24 11 0
>
and access "result values as separate entities" with indices.
For example, here xt is a 2 X 3 matrix and the first row, last
column is:
> xt [ 1 , 3 ]
[1] 9
>
and the entire first row is:
> xt [ 1 , 1:3 ]
S M L
99 15 9
>
> ...Does a weight function to be use with ct
> exist? I need to use a vector that
> represents a weight for my data....
Are you saying you have frequency weights? Cant you just multiply
your count matrix by your weights? Like,
> uw <- xt / 9
> uw
S M L
Thin 11.00 1.67 1
Thick 2.67 1.22 0
> uw * 9
S M L
Thin 99 15 9
Thick 24 11 0
>
or
> wt <- matrix ( c ( 10 , 20 , 30 , 40 , 50 , 60 ) , nrow = 2 ,
byrow=F)
> wt
[,1] [,2] [,3]
[1,] 10 30 50
[2,] 20 40 60
> xt * wt
S M L
Thin 990 450 450
Thick 480 440 0
>
--
David Huffer
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