Hi All, I would like to ask if it possible to start indexing a vector from 0: x = 1:10 y = c(0,0,3,4,5,6,0,8,9,10) I need to use y as an index to extract the values of x, BUT I cannot cull/transform the 0s. What I would like is to start counting the elements of x 0:9 rather than 1:10. Would this be at all possible? Regards, Federico Calboli -- Federico C. F. Calboli Department of Epidemiology and Public Health Imperial College, St. Mary's Campus Norfolk Place, London W2 1PG Tel +44 (0)20 75941602 Fax +44 (0)20 75943193 f.calboli [.a.t] imperial.ac.uk f.calboli [.a.t] gmail.com
indexing a vector starting from 0
3 messages · Federico Calboli, Sean Davis, Peter Dalgaard
On Jul 24, 2005, at 4:29 PM, Federico Calboli wrote:
Hi All, I would like to ask if it possible to start indexing a vector from 0: x = 1:10 y = c(0,0,3,4,5,6,0,8,9,10) I need to use y as an index to extract the values of x, BUT I cannot cull/transform the 0s. What I would like is to start counting the elements of x 0:9 rather than 1:10. Would this be at all possible?
Is there a reason why you can't add 1 to the x indices, like: x[y+1] Otherwise, you could use a list. Sean
Federico Calboli <f.calboli at imperial.ac.uk> writes:
Hi All, I would like to ask if it possible to start indexing a vector from 0: x = 1:10 y = c(0,0,3,4,5,6,0,8,9,10) I need to use y as an index to extract the values of x, BUT I cannot cull/transform the 0s. What I would like is to start counting the elements of x 0:9 rather than 1:10. Would this be at all possible?
There's a 0array package on CRAN, but why not just add 1 to the index?
x[y+1]
[1] 1 1 4 5 6 7 1 9 10 NA In general, 0-based indexing is possible, but messes with other things in R, most obviously negative indexes, but also constructions that use match(...., nomatch=0)
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