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*                                                            *
* prison.do                                                  *
*                                                            *
* PURPOSE:  this will read the data and perform 2x2 analysis *
*                                                            *
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*
* NOTE:  to read "string" or character variables from a file
*        we need to tell STATA that the specific variable
*        is character.  Below the text "str8" that preceeds
*        the variable name "hivS" is used to indicate that this
*        variable is string variable with at most 8 characters.
*
infile str8 hivS str8 ivduS using u:\DEPT\513\WK1\prison.dat

*
* look at the character variables
*
tabulate hivS ivduS

*
* recode character into numeric
*
encode hivS, generate(hiv)
*
* NOTE:  the command "encode" will take the character
*        variable and convert it to integers (1,2...)
*        based on alphabetic order.  Thus, "negative"
*        will be coded as 1 and "positive" as 2.
*        We then recode this as 0 and 1.
recode hiv 1=0 2=1
label define hlabs 0 "hiv-" 1 "hiv+"
label values hiv hlabs

*
* make sure that recoding has worked!
*
tabulate hivS hiv

*
* Now recode the ivduS variable...
* 
encode ivduS, generate(ivdu)
recode ivdu 1=0 2=1
label define dlabs 0 "IVDU-no" 1 "IVDU-yes"
label values ivdu dlabs

tabulate ivduS ivdu

*
* Now you are set to use cs, cc, etc.
*