On Oct 12, 2010, at 1:58 PM, David Winsemius wrote:
And ...
?which
which(abs(x-y) >0) # or if these are subject to FAQ 7.31, then
which( zapsmall( abs(x-y)) > 0 )
.. for second part of question.
THe help page answer would be along these lines:
if ( isTRUE(all.equal( x, y)) {"equal"} else{
all.equal( x, y)}
My zapsmall method is not robust to differences in length or NA
entries, but those can be added to the test criteria. (And it seems
possible that other gotcha's are lurking in the weeds.)
The method of embedding in a dataframe is going to be really slow.
require(rbenchmark)
benchmark(
all_eq = {isTRUE(all.equal.numeric(x,y))}, # not much faster than
just all.equal
zapper = {all( c(length(x) == length(y),
is.na(x)==is.na(y),
zapsmall(na.omit(x)-na.omit(y)) == 0 )
)},
dfrm = {compare<-data.frame(1:length(x),x,y);
differences<-compare$id[x!=y];
is.null(differences)},
replications=1000)
test replications elapsed relative user.self sys.self user.child
sys.child
1 all_eq 1000 0.233 3.328571 0.233 0.001
0 0
3 dfrm 1000 0.771 11.014286 0.771 0.002
0 0
2 zapper 1000 0.070 1.000000 0.070 0.001
0 0
And for most real applications, isTRUE(all.equal(x,y)) is going to be
the way to go.
-- David.
On Oct 12, 2010, at 1:43 PM, Bert Gunter wrote:
Try preusing an Intro to R for such elementary questions, please.
Also
the R Help facility.
But...
?identical ##(oddly enough...)
?"=="
But beware numerical issues -- see R FAQ 7.31.
-- Bert
On Tue, Oct 12, 2010 at 10:35 AM, ANJAN PURKAYASTHA
<[email protected]> wrote:
Hi,
I have two vectors, each of length 45000.
How do I compare the vectors to ascertain if they are identical.
Secondly if
they are NOT identical, how do I determine the indices of
positions at which
the vectors differ?
Thanks,
Anjan
--
===================================
anjan purkayastha, phd.
research associate
fas center for systems biology,
harvard university
52 oxford street
cambridge ma 02138
phone-703.740.6939
===================================
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______________________________________________
[email protected] mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
--
Bert Gunter
Genentech Nonclinical Biostatistics
______________________________________________
[email protected] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
David Winsemius, MD
West Hartford, CT
______________________________________________
[email protected] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
David Winsemius, MD
West Hartford, CT
______________________________________________
[email protected] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
