Juliet Ndukum
2010-Mar-05 03:59 UTC
[R] Selecting rows of a matrix based on some condition on the columns
The data set consists of two sets of matrices, as labelled by the columns, T's and C's.> xyx T1 T2 T3 T4 T5 C1 C2 C3 C4 C5 [1,] 50 0.00 0.00 33.75 0.00 0.00 0.00 36.76 0.00 35.26 0.00 [2,] 13 34.41 0.00 0.00 36.64 32.86 34.11 35.80 37.74 0.00 0.00 [3,] 14 35.85 0.00 33.88 36.68 34.88 34.58 0.00 32.75 37.45 0.00 [4,] 33 34.56 0.00 0.00 36.00 0.00 0.00 36.56 0.00 34.83 0.00 [5,] 66 36.38 37.42 0.00 32.47 34.05 0.00 0.00 0.00 0.00 0.00 [6,] 22 0.00 0.00 31.07 31.63 37.51 0.00 39.34 34.91 35.51 0.00 [7,] 25 0.00 0.00 0.00 36.11 34.24 0.00 34.07 32.72 0.00 0.00 [8,] 9 33.63 0.00 38.43 0.00 35.72 32.95 36.40 38.57 34.19 32.47 [9,] 87 35.22 0.00 0.00 35.31 0.00 0.00 34.55 35.14 38.12 0.00 [10,] 99 0.00 0.00 34.94 0.00 0.00 33.54 0.00 34.39 34.54 0.00 First, I wish to select for each row, all columns that have at least a T and a C. Based on the code below, I got exactly what I need.> t1all <- apply(xy,1,function(x) any((x[2]>0|x[3]>0|x[4]>0|x[5]>0|x[6]>0)&(x[7]>0 |x[8]>0 |x[9]>0|x[10]>0|x[11]>0))) > mat.t1all <- xy[t1all,] > mat.t1allx T1 T2 T3 T4 T5 C1 C2 C3 C4 C5 [1,] 50 0.00 0 33.75 0.00 0.00 0.00 36.76 0.00 35.26 0.00 [2,] 13 34.41 0 0.00 36.64 32.86 34.11 35.80 37.74 0.00 0.00 [3,] 14 35.85 0 33.88 36.68 34.88 34.58 0.00 32.75 37.45 0.00 [4,] 33 34.56 0 0.00 36.00 0.00 0.00 36.56 0.00 34.83 0.00 [5,] 22 0.00 0 31.07 31.63 37.51 0.00 39.34 34.91 35.51 0.00 [6,] 25 0.00 0 0.00 36.11 34.24 0.00 34.07 32.72 0.00 0.00 [7,] 9 33.63 0 38.43 0.00 35.72 32.95 36.40 38.57 34.19 32.47 [8,] 87 35.22 0 0.00 35.31 0.00 0.00 34.55 35.14 38.12 0.00 [9,] 99 0.00 0 34.94 0.00 0.00 33.54 0.00 34.39 34.54 0.00 Then, I need the rows for which there are at least two T's and two C's. Using a similar code as above, I get the following output:> t2all <- apply(xy,1,function(x) any(((x[2]>0&x[3]>0)|(x[2]>0&x[4]>0)|+ (x[2]>0&x[5]>0)|(x[2]>0&x[6]>0)|(x[3]>0&x[4]>0)|(x[3]>0&x[5]>0)| + (x[3]>0&x[6]>0)|(x[4]>0&x[5]>0)|(x[4]>0&x[6]>0)|(x[5]>0&x[6]>0)) + + &(( (x[7]>0&x[8]>0)|(x[7]>0&x[9]>0)|(x[7]>0&x[10]>0)|(x[7]>0&x[11]>0)| + (x[8]>0&x[9]>0)|(x[8]>0&x[10]>0)|(x[8]>0&x[11]>0)|(x[9]>0&x[10]>0)| + (x[9]>0&x[11]>0)|(x[10]>0&x[11]>0) ))))> > mat.t2all <- xy[t2all,] > mat.t2allx T1 T2 T3 T4 T5 C1 C2 C3 C4 C5 [1,] 13 34.41 0 0.00 36.64 32.86 34.11 35.80 37.74 0.00 0.00 [2,] 14 35.85 0 33.88 36.68 34.88 34.58 0.00 32.75 37.45 0.00 [3,] 33 34.56 0 0.00 36.00 0.00 0.00 36.56 0.00 34.83 0.00 [4,] 22 0.00 0 31.07 31.63 37.51 0.00 39.34 34.91 35.51 0.00 [5,] 25 0.00 0 0.00 36.11 34.24 0.00 34.07 32.72 0.00 0.00 [6,] 9 33.63 0 38.43 0.00 35.72 32.95 36.40 38.57 34.19 32.47 [7,] 87 35.22 0 0.00 35.31 0.00 0.00 34.55 35.14 38.12 0.00 For three T's and three C's, I got> t3all <- apply(xy,1,function(x) any(( (x[2]>0&x[3]>0&x[4]>0)|+ (x[2]>0&x[3]>0&x[5]>0)|(x[2]>0&x[3]>0&x[6]>0)|(x[2]>0&x[4]>0&x[5]>0)| + (x[2]>0&x[4]>0&x[6])|(x[2]>0&x[5]>0&x[6]>0)| + (x[3]>0&x[4]>0&x[5]>0)|(x[3]>0&x[4]>0&x[6]>0)| + (x[4]>0&x[5]>0&x[6]>0) ) + + &( (x[7]>0&x[8]>0&x[9]>0)| + (x[7]>0&x[8]>0&x[10]>0)|(x[7]>0&x[8]>0&x[11]>0)|(x[7]>0&x[9]>0&x[10]>0)| + (x[7]>0&x[9]>0&x[11])|(x[7]>0&x[10]>0&x[11]>0)| + (x[8]>0&x[9]>0&x[10]>0)|(x[8]>0&x[9]>0&x[11]>0)| + (x[9]>0&x[10]>0&x[11]>0) ) ))> > mat.t3all <- xy[t3all,] > mat.t3allx T1 T2 T3 T4 T5 C1 C2 C3 C4 C5 [1,] 13 34.41 0 0.00 36.64 32.86 34.11 35.80 37.74 0.00 0.00 [2,] 14 35.85 0 33.88 36.68 34.88 34.58 0.00 32.75 37.45 0.00 [3,] 22 0.00 0 31.07 31.63 37.51 0.00 39.34 34.91 35.51 0.00 [4,] 9 33.63 0 38.43 0.00 35.72 32.95 36.40 38.57 34.19 32.47 Can someone help me with a better, and more efficient code that will handle this, thank you in advance for your help. JN [[alternative HTML version deleted]]
Dennis Murphy
2010-Mar-05 04:45 UTC
[R] Selecting rows of a matrix based on some condition on the columns
Hi:
The function below counts the number of positive-valued T's and C's and
tests whether each count is at least as large as the test value n:
f <- function(x, n) (sum(x[grepl("^T", names(x))] > 0) >= n)
&
(sum(x[grepl("^C", names(x))] > 0) >= n)
Apply it to xy, adding the value of the argument n in each iteration:
> xy[apply(xy, 1, f, n = 1), ]
x T1 T2 T3 T4 T5 C1 C2 C3 C4 C5
[1,] 50 0.00 0 33.75 0.00 0.00 0.00 36.76 0.00 35.26 0.00
[2,] 13 34.41 0 0.00 36.64 32.86 34.11 35.80 37.74 0.00 0.00
[3,] 14 35.85 0 33.88 36.68 34.88 34.58 0.00 32.75 37.45 0.00
[4,] 33 34.56 0 0.00 36.00 0.00 0.00 36.56 0.00 34.83 0.00
[6,] 22 0.00 0 31.07 31.63 37.51 0.00 39.34 34.91 35.51 0.00
[7,] 25 0.00 0 0.00 36.11 34.24 0.00 34.07 32.72 0.00 0.00
[8,] 9 33.63 0 38.43 0.00 35.72 32.95 36.40 38.57 34.19 32.47
[9,] 87 35.22 0 0.00 35.31 0.00 0.00 34.55 35.14 38.12 0.00
[10,] 99 0.00 0 34.94 0.00 0.00 33.54 0.00 34.39 34.54
0.00> xy[apply(xy, 1, f, n = 2), ]
x T1 T2 T3 T4 T5 C1 C2 C3 C4 C5
[2,] 13 34.41 0 0.00 36.64 32.86 34.11 35.80 37.74 0.00 0.00
[3,] 14 35.85 0 33.88 36.68 34.88 34.58 0.00 32.75 37.45 0.00
[4,] 33 34.56 0 0.00 36.00 0.00 0.00 36.56 0.00 34.83 0.00
[6,] 22 0.00 0 31.07 31.63 37.51 0.00 39.34 34.91 35.51 0.00
[7,] 25 0.00 0 0.00 36.11 34.24 0.00 34.07 32.72 0.00 0.00
[8,] 9 33.63 0 38.43 0.00 35.72 32.95 36.40 38.57 34.19 32.47
[9,] 87 35.22 0 0.00 35.31 0.00 0.00 34.55 35.14 38.12
0.00> xy[apply(xy, 1, f, n = 3), ]
x T1 T2 T3 T4 T5 C1 C2 C3 C4 C5
[2,] 13 34.41 0 0.00 36.64 32.86 34.11 35.80 37.74 0.00 0.00
[3,] 14 35.85 0 33.88 36.68 34.88 34.58 0.00 32.75 37.45 0.00
[6,] 22 0.00 0 31.07 31.63 37.51 0.00 39.34 34.91 35.51 0.00
[8,] 9 33.63 0 38.43 0.00 35.72 32.95 36.40 38.57 34.19 32.47
HTH,
Dennis
On Thu, Mar 4, 2010 at 7:59 PM, Juliet Ndukum <jpntsang@yahoo.com> wrote:
> The data set consists of two sets of matrices, as labelled by the columns,
> T's and C's.
>
> > xy
> x T1 T2 T3 T4 T5 C1 C2 C3 C4 C5
> [1,] 50 0.00 0.00 33.75 0.00 0.00 0.00 36.76 0.00 35.26 0.00
> [2,] 13 34.41 0.00 0.00 36.64 32.86 34.11 35.80 37.74 0.00 0.00
> [3,] 14 35.85 0.00 33.88 36.68 34.88 34.58 0.00 32.75 37.45 0.00
> [4,] 33 34.56 0.00 0.00 36.00 0.00 0.00 36.56 0.00 34.83 0.00
> [5,] 66 36.38 37.42 0.00 32.47 34.05 0.00 0.00 0.00 0.00 0.00
> [6,] 22 0.00 0.00 31.07 31.63 37.51 0.00 39.34 34.91 35.51 0.00
> [7,] 25 0.00 0.00 0.00 36.11 34.24 0.00 34.07 32.72 0.00 0.00
> [8,] 9 33.63 0.00 38.43 0.00 35.72 32.95 36.40 38.57 34.19 32.47
> [9,] 87 35.22 0.00 0.00 35.31 0.00 0.00 34.55 35.14 38.12 0.00
> [10,] 99 0.00 0.00 34.94 0.00 0.00 33.54 0.00 34.39 34.54 0.00
>
> First, I wish to select for each row, all columns that have at least a T
> and a C. Based on the code below, I got exactly what I need.
>
> > t1all <- apply(xy,1,function(x)
> any((x[2]>0|x[3]>0|x[4]>0|x[5]>0|x[6]>0)&(x[7]>0
|x[8]>0
> |x[9]>0|x[10]>0|x[11]>0)))
> > mat.t1all <- xy[t1all,]
> > mat.t1all
> x T1 T2 T3 T4 T5 C1 C2 C3 C4 C5
> [1,] 50 0.00 0 33.75 0.00 0.00 0.00 36.76 0.00 35.26 0.00
> [2,] 13 34.41 0 0.00 36.64 32.86 34.11 35.80 37.74 0.00 0.00
> [3,] 14 35.85 0 33.88 36.68 34.88 34.58 0.00 32.75 37.45 0.00
> [4,] 33 34.56 0 0.00 36.00 0.00 0.00 36.56 0.00 34.83 0.00
> [5,] 22 0.00 0 31.07 31.63 37.51 0.00 39.34 34.91 35.51 0.00
> [6,] 25 0.00 0 0.00 36.11 34.24 0.00 34.07 32.72 0.00 0.00
> [7,] 9 33.63 0 38.43 0.00 35.72 32.95 36.40 38.57 34.19 32.47
> [8,] 87 35.22 0 0.00 35.31 0.00 0.00 34.55 35.14 38.12 0.00
> [9,] 99 0.00 0 34.94 0.00 0.00 33.54 0.00 34.39 34.54 0.00
>
> Then, I need the rows for which there are at least two T's and two
C's.
> Using a similar code as above, I get the following output:
>
> > t2all <- apply(xy,1,function(x)
any(((x[2]>0&x[3]>0)|(x[2]>0&x[4]>0)|
> +
(x[2]>0&x[5]>0)|(x[2]>0&x[6]>0)|(x[3]>0&x[4]>0)|(x[3]>0&x[5]>0)|
> +
(x[3]>0&x[6]>0)|(x[4]>0&x[5]>0)|(x[4]>0&x[6]>0)|(x[5]>0&x[6]>0))
> +
> + &((
(x[7]>0&x[8]>0)|(x[7]>0&x[9]>0)|(x[7]>0&x[10]>0)|(x[7]>0&x[11]>0)|
> +
(x[8]>0&x[9]>0)|(x[8]>0&x[10]>0)|(x[8]>0&x[11]>0)|(x[9]>0&x[10]>0)|
> + (x[9]>0&x[11]>0)|(x[10]>0&x[11]>0) ))))
> >
> > mat.t2all <- xy[t2all,]
> > mat.t2all
> x T1 T2 T3 T4 T5 C1 C2 C3 C4 C5
> [1,] 13 34.41 0 0.00 36.64 32.86 34.11 35.80 37.74 0.00 0.00
> [2,] 14 35.85 0 33.88 36.68 34.88 34.58 0.00 32.75 37.45 0.00
> [3,] 33 34.56 0 0.00 36.00 0.00 0.00 36.56 0.00 34.83 0.00
> [4,] 22 0.00 0 31.07 31.63 37.51 0.00 39.34 34.91 35.51 0.00
> [5,] 25 0.00 0 0.00 36.11 34.24 0.00 34.07 32.72 0.00 0.00
> [6,] 9 33.63 0 38.43 0.00 35.72 32.95 36.40 38.57 34.19 32.47
> [7,] 87 35.22 0 0.00 35.31 0.00 0.00 34.55 35.14 38.12 0.00
>
> For three T's and three C's, I got
>
> > t3all <- apply(xy,1,function(x) any((
(x[2]>0&x[3]>0&x[4]>0)|
> +
(x[2]>0&x[3]>0&x[5]>0)|(x[2]>0&x[3]>0&x[6]>0)|(x[2]>0&x[4]>0&x[5]>0)|
> +
(x[2]>0&x[4]>0&x[6])|(x[2]>0&x[5]>0&x[6]>0)|
> +
(x[3]>0&x[4]>0&x[5]>0)|(x[3]>0&x[4]>0&x[6]>0)|
> + (x[4]>0&x[5]>0&x[6]>0) )
> +
> + &( (x[7]>0&x[8]>0&x[9]>0)|
> +
(x[7]>0&x[8]>0&x[10]>0)|(x[7]>0&x[8]>0&x[11]>0)|(x[7]>0&x[9]>0&x[10]>0)|
> +
(x[7]>0&x[9]>0&x[11])|(x[7]>0&x[10]>0&x[11]>0)|
> +
(x[8]>0&x[9]>0&x[10]>0)|(x[8]>0&x[9]>0&x[11]>0)|
> + (x[9]>0&x[10]>0&x[11]>0) ) ))
> >
> > mat.t3all <- xy[t3all,]
> > mat.t3all
> x T1 T2 T3 T4 T5 C1 C2 C3 C4 C5
> [1,] 13 34.41 0 0.00 36.64 32.86 34.11 35.80 37.74 0.00 0.00
> [2,] 14 35.85 0 33.88 36.68 34.88 34.58 0.00 32.75 37.45 0.00
> [3,] 22 0.00 0 31.07 31.63 37.51 0.00 39.34 34.91 35.51 0.00
> [4,] 9 33.63 0 38.43 0.00 35.72 32.95 36.40 38.57 34.19 32.47
>
>
> Can someone help me with a better, and more efficient code that will handle
> this, thank you in advance for your help.
> JN
>
>
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@r-project.org 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.
>
[[alternative HTML version deleted]]
David Winsemius
2010-Mar-05 04:49 UTC
[R] Selecting rows of a matrix based on some condition on the columns
On Mar 4, 2010, at 10:59 PM, Juliet Ndukum wrote:> The data set consists of two sets of matrices, as labelled by the > columns, T's and C's. > >> xy > x T1 T2 T3 T4 T5 C1 C2 C3 C4 C5 > [1,] 50 0.00 0.00 33.75 0.00 0.00 0.00 36.76 0.00 35.26 0.00 > [2,] 13 34.41 0.00 0.00 36.64 32.86 34.11 35.80 37.74 0.00 0.00 > [3,] 14 35.85 0.00 33.88 36.68 34.88 34.58 0.00 32.75 37.45 0.00 > [4,] 33 34.56 0.00 0.00 36.00 0.00 0.00 36.56 0.00 34.83 0.00 > [5,] 66 36.38 37.42 0.00 32.47 34.05 0.00 0.00 0.00 0.00 0.00 > [6,] 22 0.00 0.00 31.07 31.63 37.51 0.00 39.34 34.91 35.51 0.00 > [7,] 25 0.00 0.00 0.00 36.11 34.24 0.00 34.07 32.72 0.00 0.00 > [8,] 9 33.63 0.00 38.43 0.00 35.72 32.95 36.40 38.57 34.19 32.47 > [9,] 87 35.22 0.00 0.00 35.31 0.00 0.00 34.55 35.14 38.12 0.00 > [10,] 99 0.00 0.00 34.94 0.00 0.00 33.54 0.00 34.39 34.54 0.00 > > First, I wish to select for each row, all columns that have at least > a T and a C. Based on the code below, I got exactly what I need. > >> t1all <- apply(xy,1,function(x) any((x[2]>0|x[3]>0|x[4]>0|x[5]>0| >> x[6]>0)&(x[7]>0 |x[8]>0 |x[9]>0|x[10]>0|x[11]>0))) >> mat.t1all <- xy[t1all,] >> mat.t1all > x T1 T2 T3 T4 T5 C1 C2 C3 C4 C5 > [1,] 50 0.00 0 33.75 0.00 0.00 0.00 36.76 0.00 35.26 0.00 > [2,] 13 34.41 0 0.00 36.64 32.86 34.11 35.80 37.74 0.00 0.00 > [3,] 14 35.85 0 33.88 36.68 34.88 34.58 0.00 32.75 37.45 0.00 > [4,] 33 34.56 0 0.00 36.00 0.00 0.00 36.56 0.00 34.83 0.00 > [5,] 22 0.00 0 31.07 31.63 37.51 0.00 39.34 34.91 35.51 0.00 > [6,] 25 0.00 0 0.00 36.11 34.24 0.00 34.07 32.72 0.00 0.00 > [7,] 9 33.63 0 38.43 0.00 35.72 32.95 36.40 38.57 34.19 32.47 > [8,] 87 35.22 0 0.00 35.31 0.00 0.00 34.55 35.14 38.12 0.00 > [9,] 99 0.00 0 34.94 0.00 0.00 33.54 0.00 34.39 34.54 0.00 > > Then, I need the rows for which there are at least two T's and two > C's. Using a similar code as above, I get the following output: > >> t2all <- apply(xy,1,function(x) any(((x[2]>0&x[3]>0)|(x[2]>0&x[4]>0)| > + (x[2]>0&x[5]>0)|(x[2]>0&x[6]>0)|(x[3]>0&x[4]>0)|(x[3]>0&x[5]>0)| > + (x[3]>0&x[6]>0)|(x[4]>0&x[5]>0)|(x[4]>0&x[6]>0)|(x[5]>0&x[6]>0)) > + > + &(( (x[7]>0&x[8]>0)|(x[7]>0&x[9]>0)|(x[7]>0&x[10]>0)| > (x[7]>0&x[11]>0)| > + (x[8]>0&x[9]>0)|(x[8]>0&x[10]>0)|(x[8]>0&x[11]>0)|(x[9]>0&x[10]>0)| > + (x[9]>0&x[11]>0)|(x[10]>0&x[11]>0) )))) >> >> mat.t2all <- xy[t2all,] >> mat.t2all > x T1 T2 T3 T4 T5 C1 C2 C3 C4 C5 > [1,] 13 34.41 0 0.00 36.64 32.86 34.11 35.80 37.74 0.00 0.00 > [2,] 14 35.85 0 33.88 36.68 34.88 34.58 0.00 32.75 37.45 0.00 > [3,] 33 34.56 0 0.00 36.00 0.00 0.00 36.56 0.00 34.83 0.00 > [4,] 22 0.00 0 31.07 31.63 37.51 0.00 39.34 34.91 35.51 0.00 > [5,] 25 0.00 0 0.00 36.11 34.24 0.00 34.07 32.72 0.00 0.00 > [6,] 9 33.63 0 38.43 0.00 35.72 32.95 36.40 38.57 34.19 32.47 > [7,] 87 35.22 0 0.00 35.31 0.00 0.00 34.55 35.14 38.12 0.00 > > For three T's and three C's, I got > >> t3all <- apply(xy,1,function(x) any(( (x[2]>0&x[3]>0&x[4]>0)| > + (x[2]>0&x[3]>0&x[5]>0)|(x[2]>0&x[3]>0&x[6]>0)| > (x[2]>0&x[4]>0&x[5]>0)| > + (x[2]>0&x[4]>0&x[6])|(x[2]>0&x[5]>0&x[6]>0)| > + (x[3]>0&x[4]>0&x[5]>0)|(x[3]>0&x[4]>0&x[6]>0)| > + (x[4]>0&x[5]>0&x[6]>0) ) > + > + &( (x[7]>0&x[8]>0&x[9]>0)| > + (x[7]>0&x[8]>0&x[10]>0)|(x[7]>0&x[8]>0&x[11]>0)| > (x[7]>0&x[9]>0&x[10]>0)| > + (x[7]>0&x[9]>0&x[11])|(x[7]>0&x[10]>0&x[11]>0)| > + (x[8]>0&x[9]>0&x[10]>0)|(x[8]>0&x[9]>0&x[11]>0)| > + (x[9]>0&x[10]>0&x[11]>0) ) )) >> >> mat.t3all <- xy[t3all,] >> mat.t3all > x T1 T2 T3 T4 T5 C1 C2 C3 C4 C5 > [1,] 13 34.41 0 0.00 36.64 32.86 34.11 35.80 37.74 0.00 0.00 > [2,] 14 35.85 0 33.88 36.68 34.88 34.58 0.00 32.75 37.45 0.00 > [3,] 22 0.00 0 31.07 31.63 37.51 0.00 39.34 34.91 35.51 0.00 > [4,] 9 33.63 0 38.43 0.00 35.72 32.95 36.40 38.57 34.19 32.47 > > > Can someone help me with a better, and more efficient code that will > handle this, thank you in advance for your help. > JN> xy <- data.matrix(read.table(textConnection(" + x T1 T2 T3 T4 T5 C1 C2 C3 C4 C5 + 50 0.00 0.00 33.75 0.00 0.00 0.00 36.76 0.00 35.26 0.00 + 13 34.41 0.00 0.00 36.64 32.86 34.11 35.80 37.74 0.00 0.00 + 14 35.85 0.00 33.88 36.68 34.88 34.58 0.00 32.75 37.45 0.00 + 33 34.56 0.00 0.00 36.00 0.00 0.00 36.56 0.00 34.83 0.00 + 66 36.38 37.42 0.00 32.47 34.05 0.00 0.00 0.00 0.00 0.00 + 22 0.00 0.00 31.07 31.63 37.51 0.00 39.34 34.91 35.51 0.00 + 25 0.00 0.00 0.00 36.11 34.24 0.00 34.07 32.72 0.00 0.00 + 9 33.63 0.00 38.43 0.00 35.72 32.95 36.40 38.57 34.19 32.47 + 87 35.22 0.00 0.00 35.31 0.00 0.00 34.55 35.14 38.12 0.00 + 99 0.00 0.00 34.94 0.00 0.00 33.54 0.00 34.39 34.54 0.00"), header=TRUE) ) These two vectors should give more economical summary objects with which to work: > rowSums(xy[, grep("T", colnames(xy))] > 0) [1] 1 3 4 2 4 3 2 3 2 1 > rowSums(xy[, grep("C", colnames(xy))] > 0) [1] 2 3 3 2 0 3 2 5 3 3 Or if you want to see them side by side: > cbind(rowSums(xy[, grep("T", colnames(xy))] > 0), rowSums(xy[, grep("C", colnames(xy))] > 0) ) [,1] [,2] [1,] 1 2 [2,] 3 3 [3,] 4 3 [4,] 2 2 [5,] 4 0 [6,] 3 3 [7,] 2 2 [8,] 3 5 [9,] 2 3 [10,] 1 3> --David Winsemius, MD Heritage Laboratories West Hartford, CT