[R] diff question
tring at gvdnet.dk
Sun Jan 11 09:29:26 CET 2015
R version 3.1.1 (2014-07-10) -- "Sock it to Me"
Copyright (C) 2014 The R Foundation for Statistical Computing
Platform: x86_64-w64-mingw32/x64 (64-bit)
Dear friends - I have a small problem with diff (I guess)
I made a sequence with fixed interval between consecutive elements - and
hence thought the diff would be as specified
but had a vector with apparently identical 12 elements returned from diff
tt <- seq(0,20,by=0.02)
unique(diff(tt)) # 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02
Trying to see if these elements in diff were duplicated
# FALSE TRUE FALSE FALSE TRUE FALSE FALSE TRUE TRUE and from
saw that 12 of the elements in duplicated(diff(tt)) were FALSE. Would it
be expected that the first was FALSE and the rest TRUE?
|duplicated()|determines which elements of a vector or data frame are
duplicates of elements with smaller subscripts, and returns a logical
vector indicating which elements (rows) are duplicates.
All best wishes
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