[R] Newbie wants to compare 2 huge RDSs row by row.

[William Dunlap]

If your two objects have class "data.frame" (look at class(objectName)) and
they
both have the same number of columns and the same order of columns and the
column types match closely enough (use all.equal(x1, x2) for that), then
you can try
     which( rowSums( x1 != x2 ) > 0)
E.g.,
> x1 <- data.frame(X=1:5, Y=rep(c("A","B"),c(3,2)))
> x2 <- data.frame(X=c(1,2,-3,-4,5), Y=rep(c("A","B"),c(2,3)))
> x1
  X Y
1 1 A
2 2 A
3 3 A
4 4 B
5 5 B
> x2
   X Y
1  1 A
2  2 A
3 -3 B
4 -4 B
5  5 B
> which( rowSums( x1 != x2 ) > 0)
[1] 3 4

If you want to allow small numeric differences but exactly character matches
you will have to get a bit fancier.  Splitting the data.frames into
character and
numeric parts and comparing each works well.

Bill Dunlap
TIBCO Software
wdunlap tibco.com

On Sat, Jan 27, 2018 at 1:18 PM, Marsh Hardy ARA/RISK <mhardy at ara.com>
wrote:

> Hi Guys, I apologize for my rank & utter newness at R.
>
> I used summary() and found about 95 variables, both character and numeric,
> all with "Length:368842" I assume is the # of records.
>
> I'd like to know the record number (row #?) of any record where the data
> doesn't match in the 2 files of what should be the same output.
>
> Thanks in advance, M.
>
> //
> ________________________________________
> From: Ulrik Stervbo [ulrik.stervbo at gmail.com]
> Sent: Saturday, January 27, 2018 10:00 AM
> To: Eric Berger
> Cc: Marsh Hardy ARA/RISK; r-help at r-project.org
> Subject: Re: [R] Newbie wants to compare 2 huge RDSs row by row.
>
> Also, it will be easier to provide helpful information if you'd describe
> what in your data you want to compare and what you hope to get out of the
> comparison.
>
> Best wishes,
> Ulrik
>
> Eric Berger <ericjberger at gmail.com<mailto:ericjberger at gmail.com>> schrieb
> am Sa., 27. Jan. 2018, 08:18:
> Hi Marsh,
> An RDS is not a data structure such as a data.frame. It can be anything.
> For example if I want to save my objects a, b, c I could do:
> > saveRDS( list(a,b,c,), file="tmp.RDS")
> Then read them back later with
> > myList <- readRDS( "tmp.RDS" )
>
> Do you have additional information about your "RDSs" ?
>
> Eric
>
>
> On Sat, Jan 27, 2018 at 6:54 AM, Marsh Hardy ARA/RISK <mhardy at ara.com
> <mailto:mhardy at ara.com>>
> wrote:
>
> > Each RDS is 40 MBs. What's a slick code to compare them row by row, IDing
> > row numbers with mismatches?
> >
> > Thanks in advance.
> >
> > //
> >
> > ______________________________________________
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> UNSUBSCRIBE and more, see
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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.
> >
>
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>
> ______________________________________________
> R-help at r-project.org<mailto:R-help at r-project.org> mailing list -- To
> UNSUBSCRIBE and more, see
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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.
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>

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