Here is an example of adding up 2 consecutive rows, iterating through all
the row:
> x <- matrix(1:100,10)
> x
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] 1 11 21 31 41 51 61 71 81 91
[2,] 2 12 22 32 42 52 62 72 82 92
[3,] 3 13 23 33 43 53 63 73 83 93
[4,] 4 14 24 34 44 54 64 74 84 94
[5,] 5 15 25 35 45 55 65 75 85 95
[6,] 6 16 26 36 46 56 66 76 86 96
[7,] 7 17 27 37 47 57 67 77 87 97
[8,] 8 18 28 38 48 58 68 78 88 98
[9,] 9 19 29 39 49 59 69 79 89 99
[10,] 10 20 30 40 50 60 70 80 90 100
> sapply(seq(nrow(x)/2), function(z) sum(x[2*z-1,], x[2*z,]))
[1] 930 970 1010 1050 1090
>
On 6/20/06, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
>
>
> uugh : i promise that this will be my last question of the day.
> i hate to constantly bother this group but it takes me time to get familar
> with all of these functions, tricks and and manipulations.
> i appreciate everyone's patience. i used too splus a lot
> but i've gotten rusty.
>
> i have a matrix of say 200 rows and 600 columns.
>
> i have a function "getprofit" that takes two series and returns a number.
>
> getprofit<-function(series1, series2) {
> do some stufff
> return(somenumber)
>
> is there a way to do something clever so that
> i call the function, getprofit, on the first two columns
> of the matrix ( where the first column is series1 and the second column is
> series2 ), then the next two columns of the matrix,
> then the next two columns of the matrix and so on and so forth return a
> 300 by 1 ( oir 1 by 300, it doesn't matter ) vector of "somenumbers".
>
> i ( maybe stupidly ) put the data in a matrix but
> now i am thinking that wasn't a good thing to do ?
> i can change it to some thing else if i have to.
>
> thanks
>
> ______________________________________________
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>
--
Jim Holtman
Cincinnati, OH
+1 513 646 9390 (Cell)
+1 513 247 0281 (Home)
What is the problem you are trying to solve?
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