[R] Neighbour List to Matrix

[jim holtman]

Is this what you are after:

> x <- read.table(text = "ID1   IDP2   SUMVAL
+ 1   56   0.065935895
+ 1   900   0.044110185
+ 1   1409   0.196314197
+ 3   4   0.071320388
+ 3   83   0.016269564
+ 3   529   0.011359239
+ 3   883   0.012242533
+ 3   1242   0.016558924
+ 4   3   0.004307024
+ 4   7   0.004699821
+ 4   16   0.004735112
+ 5   7   0.010324926
+ 5   16   0.011250504
+ 5   498   0.009709858
+ 5   502   0.004775749
+ 5   508   0.031411560", header = TRUE)
>
> str(x)  # dataframe
'data.frame':   16 obs. of  3 variables:
 $ ID1   : int  1 1 1 3 3 3 3 3 4 4 ...
 $ IDP2  : int  56 900 1409 4 83 529 883 1242 3 7 ...
 $ SUMVAL: num  0.0659 0.0441 0.1963 0.0713 0.0163 ...
> x.m <- as.matrix(x)
> str(x.m) # matrix
 num [1:16, 1:3] 1 1 1 3 3 3 3 3 4 4 ...
 - attr(*, "dimnames")=List of 2
  ..$ : NULL
  ..$ : chr [1:3] "ID1" "IDP2" "SUMVAL"
> head(x.m)
     ID1 IDP2     SUMVAL
[1,]   1   56 0.06593589
[2,]   1  900 0.04411019
[3,]   1 1409 0.19631420
[4,]   3    4 0.07132039
[5,]   3   83 0.01626956
[6,]   3  529 0.01135924

At this point you could use 'wrtie.csv' to create a CSV file.

On Fri, Feb 17, 2012 at 1:42 PM, A J <anxusgo at hotmail.com> wrote:
> Sorry too much. I was convinced it was able to view well. So, the structure
> of my data set is something like this:
>
>
> ID1   IDP2   SUMVAL
>
> 1   56   0.065935895
> 1   900   0.044110185
> 1   1409   0.196314197
> 3   4   0.071320388
> 3   83   0.016269564
> 3   529   0.011359239
> 3   883   0.012242533
> 3   1242   0.016558924
> 4   3   0.004307024
> 4   7   0.004699821
> 4   16   0.004735112
> 5   7   0.010324926
> 5   16   0.011250504
> 5   498   0.009709858
> 5   502   0.004775749
> 5   508   0.031411560
> ...
>
>
> Summarizing: I have all data recorded in a TXT file, and I would like, after
> loading in R, transform this list into a matrix (complete matrix, not half)
> in order to export to CSV or TXT finally.
> Thank you very much for everything.
> Best,
> AJ
>
>> Date: Fri, 17 Feb 2012 13:12:55 -0500
>> Subject: Re: [R] Neighbour List to Matrix
>> From: jholtman at gmail.com
>> To: anxusgo at hotmail.com
>> CC: r-help at r-project.org
>>
>> You might want to post a better example of what your data looks like.
>> In the email, it is hard to tell how to split the data into rows that
>> can be read with three fields since it looks like the data is composed
>> of pairs of numbers.



-- 
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?
Tell me what you want to do, not how you want to do it.