[R] sort adjacency matrix

[David Winsemius]

On Apr 6, 2015, at 11:15 AM, Bert Gunter wrote:

> Not quite, David.
> 
> If I understand the OP's query, he wants the ties to be broken by the
> "lexicographic" order (with apologies if I have misused this term) of
> the 1's within the rows. Makes things a bit more interesting.

This should correct the problem:

> M <- as.matrix(m)
> M[ order(rowSums(M=="1"), 
+           apply(M, 1, paste0, collapse=".") ,
+           decreasing=TRUE), ]
      [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
 [1,]    0    1    1    1    0    0    0    0    0     0
 [2,]    0    0    0    1    1    0    1    0    0     0
 [3,]    1    0    0    0    0    0    0    0    0     0
 [4,]    1    0    0    0    0    0    0    0    0     0
 [5,]    1    0    0    0    0    0    0    0    0     0
 [6,]    0    1    0    0    0    0    0    0    0     0
 [7,]    0    1    0    0    0    0    0    0    0     0
 [8,]    0    0    0    0    1    0    0    0    0     0
 [9,]    0    0    0    0    1    0    0    0    0     0
[10,]    0    0    0    0    0    0    0    0    0     0

The original matrix was sparse and I get this error message when attempting to use 'order' in the i-argument to the `[` method for dgCMatrix: 

Error in m[order(rowSums(m == "1"), apply(m, 1, paste0, collapse = "."),  : 
  error in evaluating the argument 'i' in selecting a method for function '[': Error: not-yet-implemented method for ==(<dgCMatrix>, <character>).
 ->>  Ask the package authors to implement the missing feature.


HTH;
-- 
David.


> Have at it!
> 
> Cheers,
> Bert
> 
> Bert Gunter
> Genentech Nonclinical Biostatistics
> (650) 467-7374
> 
> "Data is not information. Information is not knowledge. And knowledge
> is certainly not wisdom."
> Clifford Stoll
> 
> 
> 
> 
> On Mon, Apr 6, 2015 at 11:09 AM, David L Carlson <dcarlson at tamu.edu> wrote:
>> The answer depends on what kind of matrix/data frame you have. That is why we encourage people to use dput() to create a copy of the sample data in their email. Some combination of order() function the rowSums() function will probably get you what you want. For example,
>> 
>> dat[order(rowSums(dat=="1"), decreasing=TRUE),]
>> 
>> or
>> 
>> dat[order(rowSums(dat), decreasing=TRUE),]
>> 
>> or
>> 
>> dat[order(rowSums(dat, na.rm=TRUE), decreasing=TRUE),]
>> 
>> Note that the order is not unique since there are ties in the number of 1s.
>> 
>> -------------------------------------
>> David L Carlson
>> Department of Anthropology
>> Texas A&M University
>> College Station, TX 77840-4352
>> 
>> 
>> -----Original Message-----
>> From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Ragia Ibrahim
>> Sent: Monday, April 6, 2015 12:18 PM
>> To: r-help at r-project.org
>> Subject: [R] sort adjacency matrix
>> 
>> Dear group
>> i have the following matrix
>> 
>> 1  . . 1 . . 1 . . . .
>> 2  . . . . . . 1 . . .
>> 3  1 . . . 1 . . 1 . 1
>> 4  . . . . . 1 . . . .
>> 5  . . 1 . . . . . . 1
>> 6  1 . . 1 . . . . 1 .
>> 7  . 1 . . . . . 1 . .
>> 8  . . 1 . . . 1 . . 1
>> 9  . . . . . 1 . . . 1
>> 10 . . 1 . 1 . . 1 1 .
>> 
>> I want to sort it according to ones in each row ascending (where max number of ones first)
>> 
>> to be as follow
>> 
>> 3  1 . . . 1 . . 1 . 1
>> 10 . . 1 . 1 . . 1 1 .
>> 6  1 . . 1 . . . . 1 .8  . . 1 . . . 1 . . 11  . . 1 . . 1 . . . .5  . . 1 . . . . . . 17  . 1 . . . . . 1 . .9  . . . . . 1 . . . 12  . . . . . . 1 . . .4  . . . . . 1 . . . .
>> 
>> how can I do this in R
>> thanks in advance
>> 
> 


David Winsemius
Alameda, CA, USA