Re: st: Re: calculating proportions

[Ekaterina Hertog <ekaterina.hertog@sociology.ox.ac.uk>]

Dear Pathmes and Oliver,
thanks a lot, great code and it solves my problems! And I learned more 
than 3 things from it
Just a small hitch:
converting numbers to proportions syntax:

gen fap=fa/`N_female'

gives an error message: 'invalid syntax'.
I went around it by creating a variable which is a constant and equals a 
total number of women in the population and using it instead of the 
local macro. I clumsy way to do it.
katya

On 21/02/2012 16:45, Pathmeswaran wrote:
> Thanks Oliver.
>
> With your help I was able to learn 3 things on my first day in statalist!
>
>    forvalues
>    `r(N)'
>    indentation in foreach/ forvalue loops
>
> *************** example code begins **************************
>
> version 8
> clear all
> set obs 7
>
> gen byte id = _n
>
> gen byte sex = 1
> replace sex = 0 in 4/7
> label def lbl_sex 0 "male" 1 "female"
> label values sex lbl_sex
>
> gen int income = 7
> replace income = 10 in 3
> replace income = 0 in 4
> replace income = 7 in 5
> replace income = 9 in 6
> replace income = 11 in 7
>
> list
>
> * I have just copied Oliver's code
>
> sort sex
> gen idm=_n if sex==0
> * idm is a unique number for each male
>
> gen fa=.
> label variable fa "Number of females with higher income"
>
> gen fb=.
> label variable fb "Number of females with lower income"
>
> gen fe=.
> label variable fe "Number of females with equal income"
>
> * The variables fa, fb&  fe are generated individually for each male
> in the following loop
> quietly{
> 	count if sex == 0
> 	local N_male = `r(N)'
>
> 	count if sex == 1
> 	local N_female = `r(N)'
>
> 	forvalues i = 1/`N_male' {
> 		egen int feabove = rank(income) if sex==1 | (sex==0&  idm==`i'), field
> 		replace fa= feabove - 1 if idm==`i'
> 		drop feabove
>
> 		egen int febelow = rank(income) if sex==1 | (sex==0&  idm==`i'), track
> 		replace fb=  febelow - 1 if idm==`i'
> 		drop febelow
>
> 		replace fe=`N_female' - ( fa+ fb) if idm==`i'
> 	}
> }
>
> * Converting the numbers to proportions
>
> gen fap=fa/`N_female'
> label variable fap "Proportion of females with higher income"
>
> gen fbp=fb/`N_female'
> label variable fbp "Proportion of females with lower income"
>
> gen fep=fe/`N_female'
> label variable fep "Proportion of females with equal income"
>
> **************** example code ends ***************************
>
>
> With regards,
>
> Pathmes
>
>
> Prof A Pathmeswaran
> Professor in Public Health
> Faculty of Medicine, University of Kelaniya
> Ragama, Sri Lanka
> +94 11 295 3411
>
> "Not everything that counts can be counted and not everything that can
> be counted counts"
>
>
>
>
>
> On 21 February 2012 21:09, Oliver Jones<ojones@wiwi.uni-bielefeld.de>  wrote:
> > Hi Pathemes,
> >
> > your code looks good to me, but I'm no programmer.
> >
> > I just have two very minor and highly subjective suggestions:
> >
> >
> > 1.
> > in the foreach statement use a local to tell Stata the end of the numlist,
> > i.e.
> > count if sex == 0
> > local N_male = `r(N)'
> > foreach i of numlist 1/`N_male' {
> > and by the way in this case it might be more appropriate to use forvalues
> > insteed, which is the fastest way to loop over consecutive values, such as
> > looping over numbers from 1 to k. (From the Stata Help to foreach)
> >
> >
> > 2.
> > Indent after the foreach / forvalues statement, i.e.
> > forvalues i = 1/`N_male' {
> >         code
> >         code
> >         code
> > }
> >
> > Best
> > Oliver
> *
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