st: RE: RE: scalar do not allow -if-

[Nick Cox <n.j.cox@durham.ac.uk>]

As Scott Merryman's similar solution underlines,
the code here optimistically assumes no clash between scalar and variable names. 

Wrapping with -scalar()- means being always safe and never sorry. 

Nick 
n.j.cox@durham.ac.uk 


-----Original Message-----
From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Nick Cox
Sent: 17 November 2010 16:12
To: 'statalist@hsphsun2.harvard.edu'
Subject: st: RE: scalar do not allow -if-

A command 

... if <condition> 

applies observation by observation and can not be what you want. 

I guess that you want 

if (w1 > w2) & (w1 > w3) { 
	scalar hig = 1
}
else if (w2 > w1) & (w2 > w3) { 
	scalar hig = 2 
}
else if (w3 > w1) & (w3 > w2) {
	scalar hig = 3
} 

These sound like "w1 biggest", "w2 biggest", "w3 biggest". If there are any ties w1 == w2 | w2 == w3 your scalar will be undefined. (I've corrected what looks like a typo in your code, but not this problem with ties, which is perhaps unlikely.)  

Nick 
n.j.cox@durham.ac.uk 

Tomas Lind

In a small simulation I generate data and analyze them with 3 regression methods. In the bottom of the loop I save (among other things)

scalar b2   = exp(_b[x])	// beta	  

and then put the -scalar- values into a variable in a dataset where I collect the results from the 1000 simulated datasets. For example

quietly replace b2=scalar(b1) in `i'


That works fine. Now I want to calculate "hig" (in the bottom of the loop) and save it in the dataset with aggregated data (where w1, w2, w3 are -scalars-).

scalar hig = 1  if (w1 > w2) & (w1 > w3)		  
scalar hig = 2  if (w2 > w1) & (w2 > w3)		  
scalar hig = 3  if (w3 > w1) & (w3 > w1)	

However, -if- is not allowed in combination with  -scalar-.


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