Friday, August 24, 2012

Stata tip: a wrapper for the outsheet command that can write variable lables instead of variable names

One limitation of Stata's outsheet command is that it does not give you the option of writing variable labels instead of variable names on the first line. To solve this, I wrote an ado file that is a wrapper for the outsheet command:

// This ado file is a wrapper for the outsheet stata command that allows one to put the variable labels instead of the variable names on the first line of the file.

program define outsheet_varlabels

    syntax [varlist] using/ [,Comma DELIMiter(string) NONames NOLabel NOQuote replace VARLabels] 
    // if no varlist, that means outsheet all variables
    if ("`varlist'"=="") {
        local varlist "*"
    // Lets make sure that the delimiter is passed on to the outsheet command correctly. At the same time, I need the delimiter without quotes for the first line that I will write for the heading.
    if (`"`delimiter'"'~="") {
        local delimiterchar = `"`delimiter'"'
        local delimiter `"delimiter("`delimiter'")"'
    else {
        local delimiterchar = `","'
    // di `"new delimiter macro: `delimiter'"'
    // di `"delimiterchar = `delimiterchar'"'
    // Did the user say "noquote"? If not, then make sure the variable labels line below is double quoted
    if (`"`noquote'"'~="noquote") {
        local quote = `"""'
        // di `"use quotes: `quote'"'
    if ("`varlabels'" == "") { // If user did not specify the variable labels option, then just call outsheet as is
        outsheet `varlist' using `"`using'"', `comma' `delimiter' `nonames' `nolabel' `noquote' `replace'
    else { // Otherwise, write the variable lables instead of the variable names. Chose line1 to be variable labels
        tempfile tempoutsheetfile
        qui outsheet `varlist' using `"`tempoutsheetfile'"', `comma' `delimiter' `nonames' `nolabel' `noquotes' `replace'
        // Here, construct the first line
        local count = 0
        foreach var of varlist `varlist' {
            local varlabel : variable label `var'
            if (`"`varlabel'"'=="") {  // What if there no variable label for the label? Then use the variable name instead
                local varlabel `"`var'"'
            // di "var: `var'"
            local count = `count' + 1
            if (`count'==1) { // Don't want a comma before the first item.
                local line1heading `"`quote'`varlabel'`quote'"'
                // di `"`quote'`varlabel'`quote'"'
            else {
                local line1heading `"`line1heading'`delimiterchar'`quote'`varlabel'`quote'"'
                // di `"`line1heading'`delimiterchar'`quote'`varlabel'`quote'"'
        // di `"`line1heading'"'
        // di ""
        /* // This method does not work. It overwrites, rather than inserts
        tempname fht
        file open  `fht' using `"`using'"', read write t all
        file seek  `fht' tof
        file write `fht' _n `"`line1heading'"' _n
        file close `fht'
        // Try open tempoutsheetfile as read, the final file as write with the line1heading as the first line
        // This is the final file
        tempname fh_write
        file open `fh_write' using `"`using'"', t write all replace
        file write `fh_write' `"`line1heading'"' _n
        // Read from this and put in the final file
        tempname fh_read
        file open `fh_read' using `"`tempoutsheetfile'"', t read        
        file read `fh_read' readfileline
        local count = 0
        while r(eof)==0 {
            local count = `count' + 1
            if (`count'~=1) {
                file write `fh_write' `"`readfileline'"' _n
            file read `fh_read' readfileline
        file close `fh_write'
        file close `fh_read'       
    // di `"sytnax: `varlist' `using', `comma' `delimiter' `nonames' `nolabel' `noquotes' `replace'"'


To call this function so that it writes the variable labels instead of the variable names to the first line, call is just like you would the outsheet command, but with the varlabels option:

outsheet_varlabels using filename.csv, c replace varlabels