Interestingly, -encode- does not simply overwrite an existing value
label. Much more strangely (from my point of view), it simply adds
values to the value label, and generates the new encoded variable
appropriately. So nothing is overwritten, with respect to the
already-labeled variables.
Still, all things considered I would consider this a misfeature or
bug.Consider the following:
. use auto
(1978 Automobile Data)
. d
Contains data from auto.dta
obs: 74 1978 Automobile Data
vars: 12 27 Sep 2001 11:10
size: 3,478 (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 %8.0g origin Car type
------------------------------------------------------------------------
-------
Sorted by: foreign
**NOTE THAT THE VARIABLE foreign has value label "origin"
. encode make, gen(origin)
. d
Contains data from auto.dta
obs: 74 1978 Automobile Data
vars: 13 27 Sep 2001 11:10
size: 3,774 (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 %8.0g origin Car type
origin long %17.0g origin Make and Model
------------------------------------------------------------------------
-------
Sorted by: foreign
Note: dataset has changed since last saved
**NOW, BOTH foreign AND THE NEW VARIABLE origin
**HAVE THE VALUE LABEL "origin"
. la list origin
origin:
0 Domestic <======= original
1 Foreign <======= values
2 AMC Concord <========new values start here
3 AMC Pacer
4 AMC Spirit
5 Audi 5000
6 Audi Fox
<<snip>>
74 VW Scirocco
75 Volvo 260
**AND THE NEW origin VARIABLE BEGINS WITH "2" rather than "1":
. ta origin, nol
Make and |
Model | Freq. Percent Cum.
------------+-----------------------------------
2 | 1 1.35 1.35
3 | 1 1.35 2.70
4 | 1 1.35 4.05
5 | 1 1.35 5.41
6 | 1 1.35 6.76
7 | 1 1.35 8.11
8 | 1 1.35 9.46
<<snip>>
73 | 1 1.35 97.30
74 | 1 1.35 98.65
75 | 1 1.35 100.00
------------+-----------------------------------
Total | 74 100.00
--Nick Winter
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