{smcl}
{* 30jan2001}{...}
{hline}
help for {hi:renvars}{right:(STB-60: dm88)}
{hline}

{title:Renames variables}

{p 8 16}{cmd:renvars} [{it:varlist}] {cmd:\} {it:newvarlist} [ {cmd:,}
{cmdab:d:isplay} {cmd:test} ]

{p 8 16}{cmd:renvars} [{it:varlist}] {cmd:,} {it:transformation_option}
[ {cmdab:d:isplay} {cmd:test} {cmdab:sy:mbol(}{it:str}{cmd:)} ]

{p 12}where {it:transformation_option} is one of

{col 17}{cmdab:u:pper}{col 40}{cmdab:l:ower}

{col 17}{cmdab:pref:ix(}{it:str}{cmd:)}{col 40}{cmdab:postf:ix(}{it:str}{cmd:)} (synonym {cmdab:suff:ix(}{it:str}{cmd:)})

{col 17}{cmdab:pres:ub(}{it:str1 str2}{cmd:)}{col 40}{cmdab:posts:ub(}{it:str1 str2}{cmd:)}

{p 16}{cmdab:sub:st(}{it:str1 str2}{cmd:)}{p_end}

{col 17}{cmdab:pred:rop(}{it:#}{cmd:)}{col 40}{cmdab:postd:rop(}{it:#}{cmd:)}

{p 16}{cmdab:t:rim(}{it:#}{cmd:)}

{p 16}{cmdab:m:ap(}{it:string exp}{cmd:)}


{title:Description}

{p}{cmd:renvars} renames the variables listed in {it:varlist}.  If not specified,
{it:varlist} defaults to {cmd:_all}.

{p 4 4 4}{cmd:renvars} [{it:varlist}] {cmd:\} {it:newvarlist}  renames each variable to
the corresponding new name in {it:newvarlist}.

{p 4 4 4}{cmd:renvars} [{it:varlist}] {cmd:,} {it:transformation_option}  applies the
transformation specified to each variable name in {it:varlist}.

{p}{cmd:renvars} will not rename any variable unless all the new names
specified are acceptable as new variable names.  Variable labels, value labels,
formats, and characteristics are maintained.


{title:Options}

One of the following {it:transformation_options} may be specified:

{p 4 25}{cmd:upper}{space 15}
 converts the variable names to uppercase{p_end}
{*}{...}
{p 4 25}{cmd:lower}{space 15}
 converts the variable names to lowercase{p_end}
{*}{...}
{p 4 25}{cmd:prefix(}{it:str}{cmd:)}{space 9}
 prefixes variable names with {it:str}{p_end}
{*}{...}
{p 4 25}{cmd:postfix(}{it:str}{cmd:)}{space 8}
 postfixes variable names with {it:str}.  {cmd:suffix(}{it:str}{cmd:)}
 is an exact synonym{p_end}
{*}{...}
{p 4 25}{cmd:presub(}{it:str1 str2}{cmd:)}{space 3}
 replaces the leading string {it:str1} by {it:str2} in variable
 names.  {bind:{it:str2} may be empty}{p_end}
{*}{...}
{p 4 25}{cmd:postsub(}{it:str1 str2}{cmd:)}{space 2}
 replaces the trailing string {it:str1} by {it:str2} in variable
 names.  {bind:{it:str2} may be empty}{p_end}
{*}{...}
{p 4 25}{cmd:subst(}{it:str1 str2}{cmd:)}{space 4}
 substitutes (all occurrences of) {it:str1} by {it:str2} in variable
 names.  {bind:{it:str2} may be empty}}{p_end}
{*}{...}
{p 4 25}{cmd:predrop(}{it:#}{cmd:)}{space 10}
 removes the first {it:#} characters from variable names{p_end}
{*}{...}
{p 4 25}{cmd:postdrop(}{it:#}{cmd:)}{space 9}
 removes the last {it:#} characters from variable names{p_end}
{*}{...}
{p 4 25}{cmd:trim(}{it:#}{cmd:)}{space 13}
 keeps (at most) the first {it:#} characters from variable names,
 dropping the remaining characters{p_end}
{*}{...}
{p 4 25}{cmd:map(}{it:string_exp}{cmd:)}{space 5}
 specifies a rule for building new variable names from existing
 names.  By default {cmd:@} is the placeholder for existing names.
 This placeholder can be changed by specifying {cmd:symbol( )}.

{p 0 4}{cmd:display} specifies that each change is displayed.

{p 0 4}{cmd:test} specifies that each change is displayed but not
performed.

{p 0 4}{cmd:symbol(}{it:str}{cmd:)} specifies a symbol is to be used as a
placeholder for the existing name in the map expression.  The
default is {cmd:@}.  The symbol used should not  include characters
used in existing variable names.  It is difficult to imagine why
you might want to use this option.


{title:Examples}

{p 4 8}{inp:. renvars v1-v4 \ id  time income status}

{p 4 8}{inp:. renvars MYVAR1 MYVAR2 MYVAR3, lower}

{p 4 8}{inp:. renvars v1-v10, upper}

{p 4 8}{inp:. renvars, pref(X) test}

{p 4 8}{inp:. renvars, subs(X Y)}

{p 4 8}{inp:. renvars, predrop(1)}

{p 4 8}{inp:. renvars, map("D_" + substr("@", 1, 6))}


{title:Authors}

    Jeroen Weesie, Utrecht University, Netherlands
    J.Weesie@fss.uu.nl

    Nicholas J. Cox, University of Durham, U.K.
    n.j.cox@durham.ac.uk


{title:Also see}

 Manual:  {hi:[U] 14.3 Naming conventions}

{p 0 20}On-line:  {help rename }{space 3}specify the new name of a variable{p_end}
{p 0 20}{space 10}{help renpfix}{space 3}replaces one prefix with another prefix{p_end}
{p 0 20}{space 10}{help foreach}{space 3}for loops over a varlist