[R] x[0]: Can '0' be made an allowed index in R?

Martin Maechler m@ech|er @end|ng |rom @t@t@m@th@ethz@ch
Tue Apr 23 14:03:08 CEST 2024


>>>>> Ben Bolker 
>>>>>     on Sun, 21 Apr 2024 10:23:50 -0400 writes:

    > Also https://cran.r-project.org/package=Oarray (which is older and 
    > hence possibly more stable)

also maintained and written by a careful and really good person.
I do recommend  Oarray  as well.

Martin

    BB> On 2024-04-21 3:55 a.m., Hans W wrote:
    >> As we all know, in R indices for vectors start with 1, i.e, x[0] is not a
    >> correct expression. Some algorithms, e.g. in graph theory or combinatorics,
    >> are much easier to formulate and code if 0 is an allowed index pointing to
    >> the first element of the vector.
    >> 
    >> Some programming languages, for instance Julia (where the index for normal
    >> vectors also starts with 1), provide libraries/packages that allow the user
    >> to define an index range for its vectors, say 0:9 or 10:20 or even negative
    >> indices.
    >> 
    >> Of course, this notation would only be feasible for certain specially
    >> defined vectors. Is there a library that provides this functionality?
    >> Or is there a simple trick to do this in R? The expression 'x[0]' must
    >> be possible, does this mean the syntax of R has to be twisted somehow?
    >> 
    >> Thanks, Hans W.



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