R help - Nov 2005 - sort table

Hi,

I have a data frame named "questions" that I use to get a subset and
then a table:

failcondonly <- subset(questions, errorreason=="condition")
failcondtab <- table(failcondonly$type, failcondonly$qid,
exclude=c("ORGA", "skipped"))

The failcondtab looks like this:

        6 11 12 13 14 15 17 26 30 31 39 41
gave up 0  1  1  1  1  0  0  0  0  8  0  2
wrong   3  3  7  3  3  1  4  1  3  4  1  2

I want to sort this table according to the *sum* of the values in "gave
up" and "wrong" in reverse order. The highest value should be
first.
First would be column "31" (value 8+4=12), then column "12"
(value
1+7=8), etc.

sort(failcondtab) does not help, since it sorts the column names, not
the sum of the values of each column.

Thanks for any hint.
Claus

On Sat, 2005-11-05 at 18:04 +0100, Claus Atzenbeck
wrote:
> Hi,
> 
> I have a data frame named "questions" that I use to get a subset
and
> then a table:
> 
> failcondonly <- subset(questions, errorreason=="condition")
> failcondtab <- table(failcondonly$type, failcondonly$qid,
exclude=c("ORGA", "skipped"))
> 
> The failcondtab looks like this:
> 
>         6 11 12 13 14 15 17 26 30 31 39 41
> gave up 0  1  1  1  1  0  0  0  0  8  0  2
> wrong   3  3  7  3  3  1  4  1  3  4  1  2
> 
> I want to sort this table according to the *sum* of the values in
"gave
> up" and "wrong" in reverse order. The highest value should
be first.
> First would be column "31" (value 8+4=12), then column
"12" (value
> 1+7=8), etc.
> 
> sort(failcondtab) does not help, since it sorts the column names, not
> the sum of the values of each column.
> 
> Thanks for any hint.
> Claus

Something like the following should work:
> failcondtab[, rev(order(colSums(failcondtab)))]
        31 12 41 17 14 13 11 30 6 39 26 15
gave up  8  1  2  0  1  1  1  0 0  0  0  0
wrong    4  7  2  4  3  3  3  3 3  1  1  1


See ?order, ?rev and ?colSums.

HTH,

Marc Schwartz

On Sat, 2005-11-05 at 11:44 -0600, Marc Schwartz wrote:
> On Sat, 2005-11-05 at 18:04 +0100, Claus Atzenbeck wrote:
> > Hi,
> > 
> > I have a data frame named "questions" that I use to get a
subset and
> > then a table:
> > 
> > failcondonly <- subset(questions,
errorreason=="condition")
> > failcondtab <- table(failcondonly$type, failcondonly$qid,
exclude=c("ORGA", "skipped"))
> > 
> > The failcondtab looks like this:
> > 
> >         6 11 12 13 14 15 17 26 30 31 39 41
> > gave up 0  1  1  1  1  0  0  0  0  8  0  2
> > wrong   3  3  7  3  3  1  4  1  3  4  1  2
> > 
> > I want to sort this table according to the *sum* of the values in
"gave
> > up" and "wrong" in reverse order. The highest value
should be first.
> > First would be column "31" (value 8+4=12), then column
"12" (value
> > 1+7=8), etc.
> > 
> > sort(failcondtab) does not help, since it sorts the column names, not
> > the sum of the values of each column.
> > 
> > Thanks for any hint.
> > Claus
> 
> 
> Something like the following should work:
> 
> > failcondtab[, rev(order(colSums(failcondtab)))]
>         31 12 41 17 14 13 11 30 6 39 26 15
> gave up  8  1  2  0  1  1  1  0 0  0  0  0
> wrong    4  7  2  4  3  3  3  3 3  1  1  1
> 
> 
> See ?order, ?rev and ?colSums.
Or another, better variation, would be:
> failcondtab[, order(colSums(failcondtab), decreasing = TRUE)]
        31 12 11 13 14 17 41 6 30 15 26 39
gave up  8  1  1  1  1  0  2 0  0  0  0  0
wrong    4  7  3  3  3  4  2 3  3  1  1  1

which removes the requirement to use rev().

Marc