dataex: exactly one array nonzero

[ajay pasi]

* Example generated by -dataex-. To install: ssc install dataex
clear
input float(A B)
  24    .
  24    .
  24    .
   .    .
   .    .
   .    .
   .    .
   .    .
   .    .
   .    .
   .    .
   .    .
   .    .
   .    .
   .    .
 240    .
 240    .
 240    .
 240    .
 240    .
 450  630
 450  630
 450  630
   .    .
   .    .
   .    .
   .    .
   .    .
   .    .
   .  180
   .  180
   .  180
  90  150
  90  150
  90  150
  90  150
 240  540
 240  540
 240  540
 240  540
 240  540
 240  540
  90  120
  90  120
  90  120
  90  120
  90  120
  90  120
   .    .
   .    .
   .    .
 600  600
 600  600
 600  600
   .    .
   .    .
 350    .
 350    .
 350    .
 350    .
 350    .
   .    .
   .    .
   .    .
   .    .
   .    .
 480  480
 480  480
 480  480
 480  480
 480  480
 480  480
 160    .
 160    .
 160    .
 160    .
   .    .
   .    .
   .    .
   .    .
 180  300
 180  300
 180  300
 180  300
   .  540
 150    .
 150    .
 150    .
   .  240
   .  240
   .  240
   . 1800
   . 1800
   . 1800
   . 1800
   . 1800
1500 1800
1500 1800
1500 1800
1500 1800
end

Command to generate a dummy

if both A and B are non-zero (or non-missing value) then dummy is 1

if exactly one of A and B is zero or missing value (and the other is nonzero or non-missing value) then dummy is 0

[Leonardo Guizzetti]

You want an exclusive or operation. This is one way to do this. Note that this assumes you only care about whether the value is missing or not.

gen byte result = (!mi(A) & mi(B)) | (mi(A) & !mi(B))

If instead you want the condition to be non-missing and not zero, you can modify it in this way.

 gen byte result = ((A!=0 & !mi(A)) & (B==0 | mi(B))) | ((A==0 | mi(A)) & (B!=0 & !mi(B)))

[ajay pasi]

Thanks Leonardo.

[Nick Cox]

What do you want if both are missing or zero?

[ajay pasi]

Nick, if both are missing or zero, dummy should be missing value.

[Nick Cox]

Then you need different code. This is the simplest version I can think up.

gen count = (!missing(A) & (A != 0)) + (!missing(B) & (B != 0)) 

gen wanted = count == 2 if count > 0

[ajay pasi]

Thanks Nick.

[Hemanshu Kumar]

This question was asked and already answered here: https://www.statalist.org/forums/for...3-egen-command

[ajay pasi]

My apologies Hemanshu, just started using dataex, so posted twice ( one without, and the other with dataex). From now on, I shall post everything using dataex.