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st: RE: Comparing variables by observation

From   Nick Cox <>
To   "''" <>
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

which will usually yield something quite different from what you want. 


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).

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