[R] Creating matrix from long table in database (pivoting)

Henrique Dallazuanna wwwhsd at gmail.com
Tue Mar 2 20:03:23 CET 2010

```Or better:

reshape(cbind(DF, value = 1), v.names = 'value', idvar = 'V1', timevar
= 'V2', direction = 'wide')

On Tue, Mar 2, 2010 at 3:49 PM, Henrique Dallazuanna <wwwhsd at gmail.com> wrote:
> Try this:
>
> 1 is
> 1 the
> 1 first
> 1 row
> 2 this
> 2 is
> 2 the
> 2 send
> 2 row"))
> reshape(DF, v.names = 'V2', idvar = 'V1', timevar = 'V2', direction = 'wide')
>
> On Tue, Mar 2, 2010 at 3:35 PM, Jan Hornych <jh.hornych at gmail.com> wrote:
>> Hi all,
>>
>> I have a table in database that is very long and when simplified it has only
>> two columns in it (id, text). id is the row, and text is the column.
>> Technically the text is a term and and id is the document.
>> If simplifying this and assuming there is only one occurrence of the term
>> per the document. I shall be able to convert this into a binary matrix.
>> Table looks like this...
>>
>> *ID** **Text*
>> ------------
>> 1 this
>> 1 is
>> 1 the
>> 1 first
>> 1 row
>> 2 this
>> 2 is
>> 2 the
>> 2 send
>> 2 row
>> ...
>>
>>
>> in R I would like to have it as
>>
>> *id  this is the first second row*
>> ------------------------------------------------
>> 1     1  1   1     1          0     1
>> 2     1  1   1     0          1     1
>>
>> it would be simpler for me to do this transformation in R as I guess the
>> language is more handy as the SQL. The table in R have few dozen thousand of
>> columns and rows as well. I know how to read the data from database, but
>> just unsure if there is some suitable transformation available.
>>
>> Thank you
>> Jan
>>
>>        [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>
>
> --
> Henrique Dallazuanna
> Curitiba-Paraná-Brasil
> 25° 25' 40" S 49° 16' 22" O
>

--
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O

```