# Re: st: Creating a variable with the highest value from two othervariables

 From Christer Thrane To statalist@hsphsun2.harvard.edu Subject Re: st: Creating a variable with the highest value from two othervariables Date Sat, 13 Oct 2007 09:36:35 +0200

Thanks Joseph, but I can't get it to work. Can you se what is wrong in the assert-command

. sum X Y

Variable | Obs Mean Std. Dev. Min Max
-------------+--------------------------------------------------------
X | 364 6970.604 6315.697 100 45000
Y | 360 3978.485 4844.969 .5 50000

. list X Y if X< Y

+---------------+
| X Y |
|---------------|
30. | 2500 3000 |
34. | 7000 . |
37. | 1000 2000 |
54. | 700 1200 |
127. | 100 150 |
|---------------|
137. | 20000 50000 |
162. | 2000 . |
209. | 2000 4000 |
254. | 1000 . |
276. | 2000 3000 |
|---------------|
308. | 10000 . |
335. | 900 1090 |
441. | 30000 . |
+---------------+

. assert !missing(X) & !missing(Y)
assertion is false
r(9);

. generate byte Zstar = cond((X >= Y), X, Y)
(108 missing values generated)

. assert Zstar == Z

. sum Zstar

Variable | Obs Mean Std. Dev. Min Max
-------------+--------------------------------------------------------
Zstar | 0

Thanks again,

Christer

----- Original Message ----- From: "Joseph Coveney" <jcoveney@bigplanet.com>
To: "Statalist" <statalist@hsphsun2.harvard.edu>
Sent: Sunday, October 14, 2007 12:59 AM
Subject: Re: st: Creating a variable with the highest value from two other variables

Christer Thrane wrote:

I have two income measures, X and Y. I want to create a variable, Z, that is
equal to X for those obs where X>=Y and equal to Y for those obs where Y>X.
Like this:

id X Y Z
1 12 11 12
2 10 10 10
3 10 12 12

Is there a simple way?

--------------------------------------------------------------------------------

You can use -cond()-. You can nest -cond()-s to handle missing values.

Joseph Coveney

clear *
input byte id byte X byte Y byte Z
1 12 11 12
2 10 10 10
3 10 12 12
end
assert !missing(X) & !missing(Y)
generate byte Zstar = cond((X >= Y), X, Y) // Here
assert Zstar == Z
exit

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