[R] Comparison of vectors in a matrix

[esterhazy]

That is wonderful, now I think I am all set! Thanks again!


Tony Plate wrote:
> 
> This is a tricky data entry problem.  The right technique will depend on
> the fine details of the data, and it's not clear what those are.  E.g.,
> when you say "In my first column, for example, I have "henry" ", it's
> unclear to me whether or not the double quotes are part of the data or not
> - which is why it's nice to provide reproducible examples.
> 
> But, if you do have quoted strings in your data fields as they exist in an
> R matrix, you can do something like the following:
> 
>> # each element of the matrix x contains one or more quoted strings,
>> separated by commas
>> x <- matrix(c('"a", "b"', '"c"', '"b"', '"d"'), ncol=2,
>> dimnames=list(c("row1", "row2"), c("X","Y")))
>> x
>      X              Y      
> row1 "\"a\", \"b\"" "\"b\""
> row2 "\"c\""        "\"d\""
>> # use R's parsing and evaluation to turn '"a", "b"' into c("a", "b"), and
>> turn that
>> # into a matrix containing character vectors of various lengths.
>> matrix(lapply(parse(text=paste("c(", x, ")")), eval), ncol=ncol(x),
>> dimnames=dimnames(x))
>      X           Y  
> row1 Character,2 "b"
> row2 "c"         "d"
>> 
> 
> - Tony Plate
> 
> esterhazy wrote:
>> Yes, thanks for this, this is exactly what I want to do.
>> 
>> However, I have a remaining problem which is how to get R to understand
>> that
>> each entry in my matrix is a vector of names.
>> 
>> I have been trying to import my text file with the names in each vector
>> of
>> names enclosed in quotes and separated by commas, or separated by spaces,
>> or
>> without quotes, etc, with no luck. 
>> 
>> Everytime, R seems to consider the vector of names as just one long name.
>> 
>> In my first colum, for example, I have "henry", in the second, "mary",
>> "ruth", and in the third "mary", "joseph", and I have no idea how to get
>> R
>> to see that "mary", "ruth", for example, is composed of two strings of
>> text,
>> rather than just one.
>> 
>> Thanks for any further help!
>> 
>> http://old.nabble.com/file/p26305756/ffoexample.txt ffoexample.txt 
>> 
>> Tony Plate wrote:
>>> Nice problem!
>>>
>>> If I understand you correctly, here's how to do it (with list-based
>>> matrices):
>>>
>>>> set.seed(1)
>>>> (x <- matrix(lapply(rpois(10,2)+1, function(k) sample(letters[1:10],
>>>> size=k)), ncol=2, dimnames=list(1:5,c("A","B"))))
>>>   A           B          
>>> 1 Character,2 Character,5
>>> 2 Character,2 Character,5
>>> 3 Character,3 Character,3
>>> 4 Character,5 Character,3
>>> 5 Character,2 "i"        
>>>> x[1,1]
>>> [[1]]
>>> [1] "c" "b"
>>>
>>>> x[1,2]
>>> [[1]]
>>> [1] "c" "d" "a" "j" "f"
>>>
>>>> (y <- cbind(x, "A-B"=apply(x, 1, function(ab) setdiff(ab[[1]],
>>>> ab[[2]]))))
>>>   A           B           A-B        
>>> 1 Character,2 Character,5 "b"        
>>> 2 Character,2 Character,5 "g"        
>>> 3 Character,3 Character,3 Character,3
>>> 4 Character,5 Character,3 Character,2
>>> 5 Character,2 "i"         Character,2
>>>> y[1,3]
>>> [[1]]
>>> [1] "b"
>>>
>>> -- Tony Plate
>>>
>>> esterhazy wrote:
>>>> Hi,
>>>>
>>>> I have a matrix with two columns, and the elements of the matrix are
>>>> vectors.
>>>>
>>>> So for example, in line 3 of column 1 I have a vector v31=("marc",
>>>> "robert,
>>>> "marie").
>>>>
>>>> What I need to do is to compare all vectors in column 1 and 2, so as to
>>>> get,
>>>> for example setdiff(v31,v32) into a new column.
>>>>
>>>> Is there a way to do this in R?
>>>>
>>>> Thanks!
>>> ______________________________________________
>>> R-help at r-project.org 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.
>>>
>>>
>>
> 
> ______________________________________________
> R-help at r-project.org 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.
> 
> 

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