[R] Equivalent of Mathematica's Apply
Juan Pablo Romero Méndez
jpablo.romero at gmail.com
Tue Jun 24 21:50:37 CEST 2008
Hello,
Is there some equivalent function in R of Mathematica's "Apply"
i.e.
Apply[ f, g[a,b]] ==> f[a,b]
In concret, I have a matrix of indexes:
> ind = cbind(1:5, 1:5+5)
> ind
[,1] [,2]
[1,] 1 6
[2,] 2 7
[3,] 3 8
[4,] 4 9
[5,] 5 10
and I'd like to extract sequences 1:6, 2:7, 3:8, ..., 5:10 from a vector x.
What would be the most compact way of achieving this?
I've tried
sapply(1:5, function(i) x[ind[i,1] : ind[i,2]])
Although
sapply(1:5, function(i) x[seq(ind[i,])])
would be better (if it worked).
Regards,
Juan Pablo
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