In the function call in 'apply', you are passed the values in the rows:
> set.seed(30)
> z = matrix(rnorm(10), 5, 2)
> apply(z, 1, function(x) sum(z[x,1]*1, z[x,2]*3))
[1] -0.908321 0.00 0.00 -5.822442 -5.822442
> z
[,1] [,2]
[1,] -1.2885182 -1.5113079
[2,] -0.3476894 0
You are indeed missing something. x is _one row_ of z, not the index
specifying that row. So what you want is:
apply(z, 1, function(x)sum(x[1]*1, x[2]*3))
Thanks for including a reproducible example.
Sarah
On Tue, Apr 28, 2009 at 9:02 PM, megh wrote:
>
> Hi all, can you please clarify me what i
Hi all, can you please clarify me what is the wrong with following codes :
set.seed(30)
z = matrix(rnorm(10), 5, 2)
apply(z, 1, function(x) sum(z[x,1]*1, z[x,2]*3))
However I can not get the desired result. For example, "sum(z[1,1]*1,
z[1,2]*3)" gives -5.822442 which is actually correct. Am I mi
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