Odd Behavior Out of setdiff(...) - addition of duplicate entries is not identified

Jay,


Thanks much for the reply.    I think you are right about the prob.  
Unfortunately, I was not able to find the old emails I had  
discussing the use of the more powerful setdiff that essentially  
inherits from the base class R setdiff functionality but extends  
that functionality by now working with data.frames instead of just a  
simple array of values.  Love this functionality.

However, for the following example,
Test1_DF<-data.frame(HouseSize=c(1:100), LandLocation=c("Here"))
Test1_DF<-data.frame(HouseSize=c(1:100), LandLocation=c("Here"),  
Price = c("Low"))
Test2_DF<-rbind(Test1_DF, Test1_DF)
setdiff(Test1_DF, Test2_DF)
[1] HouseSize    LandLocation Price
<0 rows> (or 0-length row.names)

setdiff(Test2_DF, Test1_DF)

[1] HouseSize    LandLocation Price
<0 rows> (or 0-length row.names)

I was hoping for this example one of the setdiff's would have  
returned essentially Test1_DF, since it is duplicated and that is  
what is different between the two dataframes.

So, I guess I am trying to figure out a way to truely diff the  
dataframes, i.e. determine when two data.frames are different from  
one another and then receive the output of the results.

Does this capability exist in a function within a current R package  
or does it exist within a typically used pattern to create this  
functionality?

Thanks again for any feedback you can provide.


Also, I tried to determine my Session Info and the packages I have  
loaded, but I received the following:

sessionInfo()

Error in x$Priority : $ operator is invalid for atomic vectors
In addition: There were 12 warnings (use warnings() to see them)

warnings()

Warning messages:
1: In FUN(c("prob", "ggplot2", "reshape", "RColorBrewer",  ... :
 DESCRIPTION file of package 'prob' is missing or broken
2: In FUN(c("prob", "ggplot2", "reshape", "RColorBrewer",  ... :
 DESCRIPTION file of package 'ggplot2' is missing or broken
3: In FUN(c("prob", "ggplot2", "reshape", "RColorBrewer",  ... :
 DESCRIPTION file of package 'reshape' is missing or broken
4: In FUN(c("prob", "ggplot2", "reshape", "RColorBrewer",  ... :
 DESCRIPTION file of package 'RColorBrewer' is missing or broken
5: In FUN(c("prob", "ggplot2", "reshape", "RColorBrewer",  ... :
 DESCRIPTION file of package 'proto' is missing or broken
6: In FUN(c("prob", "ggplot2", "reshape", "RColorBrewer",  ... :
 DESCRIPTION file of package 'plyr' is missing or broken
7: In FUN(c("prob", "ggplot2", "reshape", "RColorBrewer",  ... :
 DESCRIPTION file of package 'nortest' is missing or broken
8: In FUN(c("prob", "ggplot2", "reshape", "RColorBrewer",  ... :
 DESCRIPTION file of package 'fBasics' is missing or broken
9: In FUN(c("prob", "ggplot2", "reshape", "RColorBrewer",  ... :
 DESCRIPTION file of package 'timeSeries' is missing or broken
10: In FUN(c("prob", "ggplot2", "reshape", "RColorBrewer",  ... :
 DESCRIPTION file of package 'timeDate' is missing or broken
11: In FUN(c("prob", "ggplot2", "reshape", "RColorBrewer",  ... :
 DESCRIPTION file of package 'vcd' is missing or broken
12: In FUN(c("prob", "ggplot2", "reshape", "RColorBrewer",  ... :
 DESCRIPTION file of package 'colorspace' is missing or broken


However, I typically load the following ones:
library(colorspace, lib.loc=RLibraryPathLocation)
library(vcd, lib.loc=RLibraryPathLocation)
library(timeDate, lib.loc=RLibraryPathLocation)
library(timeSeries, lib.loc=RLibraryPathLocation)
library(fBasics, lib.loc=RLibraryPathLocation)
library(nortest, lib.loc=RLibraryPathLocation)
library(plyr, lib.loc=RLibraryPathLocation)
library(proto, lib.loc=RLibraryPathLocation)
library(RColorBrewer, lib.loc=RLibraryPathLocation)
library(reshape, lib.loc=RLibraryPathLocation)
library(ggplot2, lib.loc=RLibraryPathLocation)
library(prob, lib.loc=RLibraryPathLocation)


--- On Fri, 5/29/09, G. Jay Kerns <gkerns at ysu.edu> wrote:

From: G. Jay Kerns <gkerns at ysu.edu>
Subject: Re: [R] Odd Behavior Out of setdiff(...) - addition of  
duplicate  entries is not identified
To: "Jason Rupert" <jasonkrupert at yahoo.com>
Cc: R-help at r-project.org
Date: Friday, May 29, 2009, 3:21 PM
Dear Jason,

On Fri, May 29, 2009 at 2:48 PM, Jason Rupert  
<jasonkrupert at yahoo.com>
wrote:

I think I am using the improved version of

setdiff(...) that handles data.frames, so I think some odd
behavior was expected but this one is escaping me.

It appears that the the addition of duplicate entries

is not caught by the setdiff(...).  Is this expected
behavior?

[snip]

Thanks in advance for any feedback.

Test1_DF<-data.frame(HouseSize=c(1:100))
Test2_DF<-rbind(Test1_DF, Test1_DF)
setdiff(Test1_DF, Test2_DF)
integer(0)
setdiff(Test2_DF, Test1_DF)
integer(0)

However,
Test3_DF<-data.frame(HouseSize=c(1:25))
setdiff(Test1_DF, Test3_DF)
 [1]  26  27  28  29  30  31  32  33  34

 35  36  37  38  39  40  41

[17]  42  43  44  45  46  47  48  49  50  51

 52  53  54  55  56  57

[33]  58  59  60  61  62  63  64  65  66  67

 68  69  70  71  72  73

[49]  74  75  76  77  78  79  80  81  82  83

 84  85  86  87  88  89

[65]  90  91  92  93  94  95  96  97  98  99

100

setdiff(Test3_DF, Test1_DF)
integer(0)

You didn't explicitly say which "improved version" of
setdiff() that
you are using, so I can only presume that you are using
the
setdiff.data.frame in the prob package.

The behaviour you are observing is expected and matches
the
base:::setdiff behaviour in the case of vectors;  cf.

x1 <- c(1:100)
x2 <- c(x1,x1)

setdiff(x1, x2)  # integer(0)
setdiff(x2, x1)  # integer(0)

x3 <- c(1:25)
setdiff(x1, x3)  # 26:100
setdiff(x3, x1)  # integer(0)

If so, is there another method or approach that should

be used to identify duplicate row entries between two
different data frames?

The R-help archives are chock full of every possible
variant of
questions (and answers) about this, and you haven't said
_exactly_
what you are looking for. In the absence of an already
posted
solution, please specify exactly what you want and I'll
wager an R
Ninja could dispatch it in moments.

Regards,
Jay









***************************************************
G. Jay Kerns, Ph.D.
Associate Professor
Department of Mathematics & Statistics
Youngstown State University
Youngstown, OH 44555-0002 USA
Office: 1035 Cushwa Hall
Phone: (330) 941-3310 Office (voice mail)
-3302 Department
-3170 FAX
E-mail: gkerns at ysu.edu
http://www.cc.ysu.edu/~gjkerns/

Jay,


Thanks much for the reply. ? ?I think you are right about the prob. Unfortunately, I was not able to find the old emails I had discussing the use of the more powerful setdiff that essentially inherits from the base class R setdiff functionality but extends that functionality by now working with data.frames instead of just a simple array of values. ?Love this functionality.

However, for the following example,
Test1_DF<-data.frame(HouseSize=c(1:100), LandLocation=c("Here"))
Test1_DF<-data.frame(HouseSize=c(1:100), LandLocation=c("Here"), Price = c("Low"))
Test2_DF<-rbind(Test1_DF, Test1_DF)
setdiff(Test1_DF, Test2_DF)
[1] HouseSize ? ?LandLocation Price
<0 rows> (or 0-length row.names)

setdiff(Test2_DF, Test1_DF)

[1] HouseSize ? ?LandLocation Price
<0 rows> (or 0-length row.names)

I was hoping for this example one of the setdiff's would have returned essentially Test1_DF, since it is duplicated and that is what is different between the two dataframes.

So, I guess I am trying to figure out a way to truely diff the dataframes, i.e. determine when two data.frames are different from one another and then receive the output of the results.

Does this capability exist in a function within a current R package or does it exist within a typically used pattern to create this functionality?

Thanks again for any feedback you can provide.

Also, I tried to determine my Session Info and the packages I have loaded, but I received the following:

sessionInfo()

Error in x$Priority : $ operator is invalid for atomic vectors