Since we will test the first sample anyway the beginning is easy:
gen Test1=Spec1
Test4 should be as close as possible to (Startdate + 608 days)
and must be > (StartDate + 61 days)
and must be < (EndDate - 91 days)
Test2 should be as close as possible to (StartDate+243 days)
and must be > (StartDate + 61 days)
and must be < (Test4 - 61 days)
Test3 should be as close as possible to the midpoint between Test3 and
Test4
and must be > (Test2 + 61 days)
and must be < (Test4 - 61days)
Thanks in advance for your help,
Elmar
*
* 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/
