This kind of thread summary is very helpful.
What what Michael calls Method 3, a -format()- option
to -todate- from SSV allows his code to be cut by one line.
Also, I don't quite understand why he recommends using -destring-
first: the help for -todate- does explain that
it can process string variables directly. You might
need -destring- if there were extraneous characters that
needed to be removed.
Nick
[email protected]
Michael McCulloch
> I recently posted a question on how to separate a string date
> into Stata
> date. I would like to share the three methods which I've learned:
>
> * 3 methods for converting a string date to Stata format
> clear
> input datedx
> 19900417
> 19880107
> 19930407
> 19880819
> 19890127
> end
>
> * METHOD 1
> tostring datedx, replace
> generate str4 dxyr1= substr(datedx,1,4)
> generate str2 dxmo1 = substr(datedx,5,6)
> generate str2 dxda1 = substr(datedx,7,8)
> destring dx*, replace
> gen datedx1 = mdy(dxmo1, dxda1, dxyr1)
> format datedx1 %d
>
> * METHOD 2 (by Maarten Buis)
> destring datedx, replace
> gen int dxyr2 = floor(datedx/10000)
> gen int dxmo2 = floor((datedx-dxyr2*10000)/100)
> gen int dxda2 = datedx - dxyr2*10000 - dxmo2*100
> gen datedx2 = mdy(dxmo2, dxda2, dxyr2)
> format datedx2 %d
>
> * METHOD 3 (by Nick Cox; first must run .ssc install todate)
> * uses the dates as numbers (i.e. use -destring- first) then
> the floor
> function.
> todate datedx, gen(datedx3) pattern(yyyymmdd)
> format datedx3 %d
> list datedx datedx1 datedx2 datedx3 in 1/5
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
