Re: [R] Creating binary variable depending on strings of two dataframes

From: David Winsemius <dwinsemius_at_comcast.net>
Date: Tue, 10 May 2011 09:09:55 -0400

On May 10, 2011, at 3:18 AM, noxyport_at_gmail.com wrote:

> On Fri, May 6, 2011 at 7:41 PM, David Winsemius <dwinsemius_at_comcast.net 
> > wrote:

>>
>> On May 6, 2011, at 11:35 AM, Pete Pete wrote:
>>
>>>
>>> Gabor Grothendieck wrote:
>>>>
>>>> On Tue, Dec 7, 2010 at 11:30 AM, Pete Pete
>>>> &lt;noxyport_at_gmail.com&gt;
>>>> wrote:
>>>>>
>>>>> Hi,
>>>>> consider the following two dataframes:
>>>>> x1=c("232","3454","3455","342","13")
>>>>> x2=c("1","1","1","0","0")
>>>>> data1=data.frame(x1,x2)
>>>>>
>>>>> y1=c("232","232","3454","3454","3455","342","13","13","13","13")
>>>>> y2=c("E1","F3","F5","E1","E2","H4","F8","G3","E1","H2")
>>>>> data2=data.frame(y1,y2)
>>>>>
>>>>> I need a new column in dataframe data1 (x3), which is either 0
>>>>> or 1
>>>>> depending if the value "E1" in y2 of data2 is true while x1=y1.
>>>>> The
>>>>> result
>>>>> of data1 should look like this:
>>>>> x1 x2 x3
>>>>> 1 232 1 1
>>>>> 2 3454 1 1
>>>>> 3 3455 1 0
>>>>> 4 342 0 0
>>>>> 5 13 0 1
>>>>>
>>>>> I think a SQL command could help me but I am too inexperienced
>>>>> with it
>>>>> to
>>>>> get there.
>>>>>
>>>>
>>>> Try this:
>>>>
>>>>> library(sqldf)
>>>>> sqldf("select x1, x2, max(y2 = 'E1') x3 from data1 d1 left join
>>>>> data2 d2
>>>>> on (x1 = y1) group by x1, x2 order by d1.rowid")
>>>>
>>>> x1 x2 x3
>>>> 1 232 1 1
>>>> 2 3454 1 1
>>>> 3 3455 1 0
>>>> 4 342 0 0
>>>> 5 13 0 1
>>>>
>>>>
>> snipped Gabor's sig
>>>
>>> That works pretty cool but I need to automate this a bit more.
>>> Consider
>>> the
>>> following example:
>>>
>>> list1=c("A01","B04","A64","G84","F19")
>>>
>>> x1=c("232","3454","3455","342","13")
>>> x2=c("1","1","1","0","0")
>>> data1=data.frame(x1,x2)
>>>
>>> y1=c("232","232","3454","3454","3455","342","13","13","13","13")
>>> y2=c("E13","B04","F19","A64","E22","H44","F68","G84","F19","A01")
>>> data2=data.frame(y1,y2)
>>>
>>> I want now to creat a loop, which creates for every value in list1
>>> a new
>>> binary variable in data1. Result should look like:
>>> x1 x2 A01 B04 A64 G84 F19
>>> 232 1 0 1 0 0 0

>>> 3454 1 0 0 1 0 1
>>> 3455 1 0 0 0 0 0
>>> 342 0 0 0 0 0 0
>>> 13 0 1 0 0 1 1
>>

>> Loops!?! We don't nee no steenking loops!
>>
>>> xtb <- with(data2, table(y1,y2))
>>> cbind(data1, xtb[match(data1$x1, rownames(xtb)), ] )
>> x1 x2 A01 A64 B04 E13 E22 F19 F68 G84 H44
>> 232 232 1 0 0 1 1 0 0 0 0 0
>> 3454 3454 1 0 1 0 0 0 1 0 0 0
>> 3455 3455 1 0 0 0 0 1 0 0 0 0
>> 342 342 0 0 0 0 0 0 0 0 0 1
>> 13 13 0 1 0 0 0 0 1 1 1 0
>>
>> I am guessing that you were to ... er, busy? ... to complete the
>> table?
>>
>> --
>>
>> David Winsemius, MD
>> West Hartford, CT
>>
>>
>
> Thanks a lot! Pretty simple. I am so much used to SQLDF right now.
>
> So how would you handle more complicated strings like that:
> y1=c("232","232", "232",  
> "3454","3454","3455","342","13","13","13","13")
> y2=c("E13","B04 A01 F19","B04","F19","A64 G84 A05","E22","H44
> C35","F68","G84","F19","A01")
> data2=data.frame(y1,y2)
>
> Where you want to extract for instance all "A01" from the strings?

I think you need either to explain what you want in more words of the English language or to offer an example of the desired output. I suspect you did not want something as simple as this:

 > A01.instances <- grep("A01" , data2$y2)  > A01.instances
[1] 2 11
 > data2[A01.instances, ]

     y1 y2
2 232 B04 A01 F19
11 13 A01

Or maybe you did?

-- 
David Winsemius, MD
West Hartford, CT

______________________________________________
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.
Received on Tue 10 May 2011 - 13:24:45 GMT

This quarter's messages: by month, or sorted: [ by date ] [ by thread ] [ by subject ] [ by author ]

All messages

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Tue 10 May 2011 - 14:20:06 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.

list of date sections of archive