{smcl}
{* 13 October 2008}{...}
{hline}
help for {hi:labgen} and {hi:labreplace}
{hline}

{title:Generate or replace variables with definitions copied to variable labels}

{p 4 10 2}
{cmd:labgen} 
[{it:typname}] 
{it:varname}
{cmd:=}
{it:exp}
[{cmd:if} {it:exp}]
[{cmd:in} {it:range}]

{p 4 10 2}
{cmd:labreplace} 
{it:varname}
{cmd:=}
{it:exp}
[{cmd:if} {it:exp}]
[{cmd:in} {it:range}]
[, {cmdab:nop:romote} ] 


{title:Description}

{p 4 4 2}{cmd:labgen} generates a new variable using {help generate},
except that the definition of the variable, i.e. whatever follows the equals sign, 
including any {help if} or {help in} qualifiers specified,
becomes the variable label. 

{p 4 4 2}{cmd:labreplace} replaces an existing variable using 
{help replace}, 
except that the definition of the variable, i.e. whatever follows the equals sign, 
including any {help if} or {help in} qualifiers specified,
becomes the variable label. 

{p 4 4 2}
Thus {cmd:labgen logy = ln(y)} creates a new variable {cmd:logy} with
variable label {cmd:ln(y)}. Similarly 
{cmd:labreplace logy = ln(y) if foo > 2} replaces variable {cmd:lny}
with a new variable label {cmd:ln(y) if foo > 2}. 


{title:Remarks}

{p 4 4 2}A first version of {cmd:labgen} was posted by Paul Lin to
Statalist on 16 July 1996. NJC posted a revision on 18 July 1996. Alan
H. Feiveson drew my attention to it once more in Statalist postings on  
25 September 2008. {cmd:labgen} as published on SSC is revised and 
{cmd:labreplace} is new as of 13 October 2008. 

{p 4 4 2}Note that the {it::lblname} syntax of {help generate} 
is not supported. 

{p 4 4 2}Exceptionally, if the definition exceeds 80 characters
in length, then the definition is inserted in {help notes} for the
variable and the variable label is a pointer to that effect. 

{p 4 4 2}For other commands in similar spirit, 
{stata search genl:search genl} and see Weesie (1997), or 
{stata search defv:search defv} and see Gleason (1997, 1999).


{title:Examples}

{p 4 8 2}{cmd:. labgen lny = ln(y)}{p_end}
{p 4 8 2}{cmd:. labreplace lny = ln(y) if bar > 2}


{title:Author}

{p 4 4 2}Nicholas J. Cox, Durham University, U.K.{break}
n.j.cox@durham.ac.uk


{title:References}

{p 4 8 2}Gleason, J.R. 1997. 
Defining variables and recording their definitions. 
{it:Stata Technical Bulletin} 40: 9{c -}10.
({it:STB Reprints} 7: 48{c -}49) 
{browse "http://www.stata.com/products/stb/journals/stb40.pdf":http://www.stata.com/products/stb/journals/stb40.pdf}

{p 4 8 2}Gleason, J.R. 1999. Update to defv. 
{it:Stata Technical Bulletin} 51: 2. 
({it:STB Reprints} 9: 14{c -}15) 
{browse "http://www.stata.com/products/stb/journals/stb51.pdf":http://www.stata.com/products/stb/journals/stb51.pdf} 

{p 4 8 2}Weesie, J. 1997. 
Automatic recording of definitions. 
{it:Stata Technical Bulletin} 35: 6{c -}7. 
({it:STB Reprints} 6: 18{c -}20) 
{browse "http://www.stata.com/products/stb/journals/stb35.pdf":http://www.stata.com/products/stb/journals/stb35.pdf}