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From |
Nick Cox <n.j.cox@durham.ac.uk> |

To |
"'statalist@hsphsun2.harvard.edu'" <statalist@hsphsun2.harvard.edu> |

Subject |
st: RE: Comparing variables by observation |

Date |
Tue, 21 Sep 2010 19:57:42 +0100 |

No code of yours allows no comment on that. Responding to the algebra given, this kind of problem is one in which Stata's syntax is inescapably long-winded. To save checking on precedence rules I tend to parenthesise aggressively: (5 >= X1) & (X1 >= X2) & (X2 >= X3) & (X3 >= 4) (X1 <= 3) & (5 <= X3) What you wrote is not illegal but it will be interpreted in terms of 1s and 0s as explained at length in http://www.stata.com/support/faqs/data/trueorfalse.html which will usually yield something quite different from what you want. Nick n.j.cox@durham.ac.uk Anisa Shyti I have three variables X1 X2 X3 (taking values from 1 to 10) and I need to compare their values, by observation, according to several conditions (which are theoretically derived) of the form, examples: (1) 5>= X1 >=X2 >=X3 >=4; (2) X1<=3 and 5<= X3. I need to evaluate each condition on the data by counting the number of times it is met, in order to classify the observations. I tried several approaches, but the total number of classified observations exceeds the total number of observations. So, I am guessing I have some redundant counts - maybe I am doing something wrong with the coding (given that the conditions are correct). * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**Re: st: RE: Comparing variables by observation***From:*Anisa Shyti <anisa.shyti@gmail.com>

**References**:**st: Comparing variables by observation***From:*Anisa Shyti <anisa.shyti@gmail.com>

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