Renzo Comolli
> On
> http://www.stata.com/statalist/archive/2003-08/msg00582.html
> Nick Cox writes "It is the user's responsibility to
> consider whether the
> copied variable label and characteristics
> also apply."
>
> In particular I want to draw the attention to the
> interaction between -numlabel- and -vreverse-
> If you first -numlabel label, add- and after -vreverse varname,
> generate(newvar)-, then the numbers in the lables will be
> wrong for newvar.
> The -vreverse- generates a new lable with the same name as
> newvar, to my
> (very modest) experience it is not possible to subsequently
> remove the
> numbers from the new lable.
>
> So (at the moment) the best way to do what people want,
> assuming they want
> the right lables on both the original variable and the new
> variable, seems to me to be
> -numlabel label, remove- -vreverse varname,
> generate(newvar)- -numlabel
> label, add- -numlabel newlabel, add-
>
> E.g.
>
> . sysuse auto, clear
> (1978 Automobile Data)
>
> . numlabel origin, add
>
> . tab foreign
>
> Car type | Freq. Percent Cum.
> ------------+-----------------------------------
> 0. Domestic | 52 70.27 70.27
> 1. Foreign | 22 29.73 100.00
> ------------+-----------------------------------
> Total | 74 100.00
>
> . tab foreign, nola
>
> Car type | Freq. Percent Cum.
> ------------+-----------------------------------
> 0 | 52 70.27 70.27
> 1 | 22 29.73 100.00
> ------------+-----------------------------------
> Total | 74 100.00
>
> . vreverse foreign, generate(Foreign)
>
> . tab Foreign
>
> Car type | Freq. Percent Cum.
> ------------+-----------------------------------
> 1. Foreign | 22 29.73 29.73
> 0. Domestic | 52 70.27 100.00
> ------------+-----------------------------------
> Total | 74 100.00
>
> . tab Foreign, nola
>
> Car type | Freq. Percent Cum.
> ------------+-----------------------------------
> 0 | 22 29.73 29.73
> 1 | 52 70.27 100.00
> ------------+-----------------------------------
> Total | 74 100.00
>
> . d
>
> Contains data from C:\STATA8\ado\base/a/auto.dta
> obs: 74 1978 Automobile Data
> vars: 13 3 Oct 2002 13:53
> size: 3,552 (99.9% of memory free)
> ------------------------------------------------------------
> ----------------
> ---
> storage display value
> variable name type format label variable label
> ------------------------------------------------------------
> ----------------
> ---
> make str18 %-18s Make and Model
> price int %8.0gc Price
> mpg int %8.0g Mileage (mpg)
> rep78 int %8.0g Repair Record 1978
> headroom float %6.1f Headroom (in.)
> trunk int %8.0g Trunk space (cu. ft.)
> weight int %8.0gc Weight (lbs.)
> length int %8.0g Length (in.)
> turn int %8.0g Turn Circle (ft.)
> displacement int %8.0g Displacement (cu. in.)
> gear_ratio float %6.2f Gear Ratio
> foreign byte %11.0g origin Car type
> Foreign byte %11.0g Foreign Car type
> ------------------------------------------------------------
> ----------------
> ---
> Sorted by: foreign
> Note: dataset has changed since last saved
>
> . numlabel Foreign, remove
> (no value label to be modified)
>
> . numlabel Foreign, remove force
> (no value label to be modified)
>
> . numlabel Foreign, add
>
> . tab Foreign
>
> Car type | Freq. Percent Cum.
> ---------------+-----------------------------------
> 0. 1. Foreign | 22 29.73 29.73
> 1. 0. Domestic | 52 70.27 100.00
> ---------------+-----------------------------------
> Total | 74 100.00
>
Renzo is of course quite right. -vreverse- (user-written) knows
nothing about what you may have done previously with -numlabel-
(official Stata).
However, although Renzo's implication here is that this is
always a nuisance, I can easily imagine situations in which
the two commands together give exactly what you want, i.e.
you want tables etc. to be in order resembling
5. Excellent
...
1. Very poor
I'll look into an adding an option or options to -vreverse-
for fixing this problem -- when it is a problem -- without
modifying the original variable's value labels.
Nick
[email protected]
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