[R] how to get column/row info from a dist object?

[Francisco J. Zagmutt]

Hi Pedro

Dist objects are visualized in your console as a matrix, but their 
structure is not quite a matrix (see str(d) in my previous example). 
Why can't you just use which(d==1.1837)? (d being your original matrix)

Regards,

Francisco


Pedro Mardones wrote:
> Thanks Francisco;
> I'm trying to avoid the step of converting a dist object into a matrix
> because I'm working with matrices of more than 5000 rows x 5000
> columns. I just was wondering if someone knew any trick to do that.
> 
> On 5/11/07, Francisco J. Zagmutt <gerifalte28 at hotmail.com> wrote:
>> But the dist object is not structured with rows and columns.  i.e.
>>
>> x=1:4
>>
>> d=dist(x)
>>   1 2 3
>> 2 1
>> 3 2 1
>> 4 3 2 1
>>
>> str(d)
>> Class 'dist'  atomic [1:6] 1 2 3 1 2 1
>>   ..- attr(*, "Size")= int 4
>>   ..- attr(*, "Diag")= logi FALSE
>>   ..- attr(*, "Upper")= logi FALSE
>>   ..- attr(*, "method")= chr "euclidean"
>>   ..- attr(*, "call")= language dist(x = x)
>>
>> So, AFAIK if you want to get references for rows and columns you need to
>> make it an object that indeed has rows and columns, i.e. a matrix.  See
>> ?which to obtain the reference you want in a matrix.
>>
>> Regards,
>>
>> Francisco
>>
>>
>> Pedro Mardones wrote:
>>> Dear R users;
>>>
>>> Is it possible to get the row and column number of a particular entry
>>> in a dist object?
>>>
>>> Let's say that I want to find the position of the value 1.1837 (the
>>> last entry on the dist object below), that is [6,3]. Can I get those
>>> values without transforming the object to a matrix?, i.e. working with
>>> the dist object only.
>>>
>>>             1                2               3
>>> 2  0.23935864
>>> 3  0.56655914 0.71923104
>>> 4  0.15272561 0.37926989 0.43931332
>>> 5  0.17728654 0.13355685 0.73025495
>>> 6  0.61783536 0.52055379 1.18374889
>>>
>>> Thanks for any idea
>>> PM
>>>
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>> ______________________________________________
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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 stat.math.ethz.ch 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.
>