[R] how can i deal with multiple response data?

[ronggui]

in a questionair i ask:
Which of the following software packages do you use for data analysis?
1 	R
2 	S-Plus
3 	SAS
4 	SPSS
5 	Stata
6 	others
(In this question, respondents are asked to mark the name of each package they use. Respondents may mark any number of packages)

and code the answer as:
                q1_R   q1_SPlus     q1_SAS    q1_SPSS   q1_Stata  q1_others   
        1.         1          0          0          0          0          1    
        2.         1          1          0          0          1          0     
        3.         0          0          0          0          1          0    
        4.         0          0          1          0          0          0    
        5.         0          0          1          0          0          1    


my question: is there any function  dealing with this data?



-- 
Department of Sociology
Fudan University,Shanghai
Blog:http://sociology.yculblog.com