Sunday, March 19, 2006

st: dropped observations after append

I have two datasets, (dset1.dta and dset2.dta). With dset1.dta, I append with the command: append using dset2.dta.

dset1.dta has: id dset agev male meduse afev1 2 1 10 1 1 1.700833 6 1 11 0 0 2.084792 15 1 11 1 0 1.499583 18 1 7 1 0 1.183437 20 1 10 1 0 1.400417

dset2.dta has: id dset agev male meduse afev1 2 0 10 1 0 -9 6 0 11 0 1 -9 15 0 11 1 1 -9 18 0 7 1 1 -9 20 0 10 1 1 -9

After I append, why are values from the first dataset dset1.dta for the variable dset==1 are dropped? id dset wheeze cough meduse afev1 male agev height anysx 2 0 0 0 0 -9 1 10 137.922 0 2 . 0 0 1 1.700833 1 10 137.922 0 6 . 0 1 0 2.084792 0 11 150.876 1 6 0 0 1 1 -9 0 11 150.876 1 15 . 0 1 0 1.499583 1 11 141.986 1 15 0 0 1 1 -9 1 11 141.986 1 18 . 0 0 0 1.183437 1 7 120.396 0 18 0 0 0 1 -9 1 7 120.396 0 20 . 0 0 0 1.400417 1 10 150.114 0 20 0 0 0 1 -9 1 10 150.114 0

Best wishes, Michael

____________________________________

Michael McCulloch Pine Street Clinic 124 Pine Street, San Anselmo, CA 94960-2674 tel 415.407.1357 fax 415.485.1065 email: mm@pinest.org web: www.pinest.org www.pinestreetfoundation.org

* * 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/


Tag:


Links to this post:

Create a Link



<< Home

This page is powered by Blogger. Isn't yours?