Changing ungrouped cases to grouped cases

As a follow up is there any way to also get the count for each combination?
For example

  y     A   B   C
  0     1    1   2
  0     1    2   1
  1     1    1   2
  0     1    1   2
  1     1    1   2
  1     1    2   1
  0     1    2   2

Should become:

  y   A  B  C  count
  2   1   1  2    4
  1   1   2  1    2
  0   1   2   2   1
.
.
.
So I would know there were 2 successes out of 4.
Thanks!
Chris



On Fri, Jul 20, 2012 at 10:41 AM, Christopher Desjardins <
cddesjardins at gmail.com> wrote:

Thanks the aggregate() command is what I was looking for.
Chris


On Thu, Jul 19, 2012 at 9:03 PM, David L Carlson <dcarlson at tamu.edu>wrote:

dtf <- read.table(text="y     A   B   C

+ 0     1    1   2
+ 0     1    2   1
+ 1     1    1   2
+ 0     1    1   2
+ 1     1    1   2
+ 1     1    2   1
+ 0     1    2   2",
+ header=TRUE)

dtagroup <- aggregate(y~A+B+C, dtf, sum)

# Gets you the groups. If you need the column/row order:

dtagroup <- dtagroup[order(dtagroup$y, decreasing=TRUE),c(4, 1:3)]

----------------------------------------------
David L Carlson
Associate Professor of Anthropology
Texas A&M University
College Station, TX 77843-4352

-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
project.org] On Behalf Of Christopher Desjardins
Sent: Thursday, July 19, 2012 7:35 PM
To: R help
Subject: [R] Changing ungrouped cases to grouped cases

Hi,
I have my data the following way:

y     A   B   C
0     1    1   2
0     1    2   1
1     1    1   2
0     1    1   2
1     1    1   2
1     1    2   1
0     1    2   2
.
.
.
And so on.  How can I make my data look like the following:
y   A  B  C
2   1   1  2
1   1   2  1
0   1   2   2
.
.
.

In other words how can I change my ungrouped cases into grouped cases?
Thanks!
Chris

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