Hi everybody. I've just been bitten by an odd inconsistency between what constitutes a legal name for a variable and a legal name for a macro. 8-bit ascii characters are apparently legal in variable names, but when used in a macro name, no macro is created.
Here's an example using the auto dataset. The first part shows that the variable name u� is legal. The second part shows that when I try to use -tempvar- to create a macro called "u�", nothing is created - when Stata gets to the next line, macro substitution means `u�' becomes ... nothing.
. do "C:\DOCUME~1\MARKSC~1\LOCALS~1\Temp\STD0l000000.tmp"
. sysuse auto, clear
(1978 Automobile Data)
.
. capture program drop legalnames
. program define legalnames
1. gen u� = mpg
2. sum u�
3. tempvar u�
4. gen `u�' = mpg
5. sum `u�'
6. end
.
. set trace on
. legalnames
----------------------------------------------- begin legalnames ---
- gen u� = mpg
- sum u�
Variable | Obs Mean Std. Dev. Min Max
-------------+--------------------------------------------------------
u� | 74 21.2973 5.785503 12 41
- tempvar u�
- gen `u�' = mpg
= gen = mpg
too few variables specified
------------------------------------------------- end legalnames ---
r(102);
end of do-file
r(102);
I can't find anything about this in the manuals, but the behavior of -tempvar- does look bug-like - if an illegal macro name is used, shouldn't -tempvar- complain?
In programs I sometimes generate macro names based on variable names, so if the naming rules are actually different for variable names and macro names, this is not a good strategy.
--Mark
Stata 9.2
Windows XP
Prof. Mark Schaffer
Director, CERT
Department of Economics
School of Management & Languages
Heriot-Watt University, Edinburgh EH14 4AS
tel +44-131-451-3494 / fax +44-131-451-3296
email: [email protected]
web: http://www.sml.hw.ac.uk/ecomes
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